1. Pre-Design
A. Appraisal
B. Design Brief
1.1. Obtain design brief
1.1.1. CIBSE guidance and tools
The lighting strategy of a building affects the building design in two often conflicting ways; it is offering visual comfort while it is increasing the solar and overall internal gains in the space. The building services engineer will have to balance the above two aspects when designing the lighting strategy.
The building services engineer should be able to influence the design brief at an early stage in terms of energy efficiency, system options, sustainability, climate change, regulations etc. There are various ways to influence the brief and the following suggested guidance provides information relevant to some of the issues related to building design.
CIBSE Guide F “Energy Efficiency in Buildings” provides information on energy efficiency issues at various design stages, including information to be used at early design stages, such as the drivers for energy efficiency (chapter 1), setting energy objectives, criteria and targets, equipment and system selection (chapter 2) and developing a design strategy (chapter 3 and 4). Furthermore, Guide F provides general information on LZC technologies (chapter 5), control strategies (chapter 6) and lighting design considerations (chapter 9). Part C of Guide F provides benchmarks of energy performance for various building applications and a series of CIBSE policy statements that reinforce the drivers for energy efficiency.
CIBSE Guide L “Sustainability” provides information on sustainability issues to help towards influencing the design brief (chapter 2), forming a sustainability strategy (chapter 3), including energy and low carbon strategy with reference to LZC technologies (§3.1), and adaptation to the impacts of climate change (§3.3).
CIBSE publications related to renewable technologies are the AM12 “Small-Scale Combined Heat and Power for Buildings”, TM25 “Understanding Building Integrated Photovoltaics and TM38 “Renewable Energy Sources for Buildings” with an accompanied simple tool to assist in initial identification of the most promising renewable sources for a given project.
SLL “Code for Lighting” and CIBSE Lighting Guide LG10 “Daylight and Window Design” provide guidance on lighting and daylight design, energy efficiency etc.
A more holistic approach of how to influence the design brief that combines energy efficiency, sustainability, cost, regulations, future performance; how certain design decisions could affect the above choices and their interrelations e.g. sustainability against capital, and whole life cost against building regulations requirements etc.
1.1.2. Weather data available for present climate conditions
At this pre-design stage of consulting with the client some general daylight statistics based on location could be used towards influencing the design brief in terms of energy efficiency and system option.
CIBSE Guide A “Environmental Design” provides solar and illuminance data for various UK locations (chapter 2, §2.7) to inform the lighting strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides solar and illuminance data (chapter 5), for the same UK locations.
The user should be looking for present day statistics of occurrence of solar radiation (global and diffuse) and illuminance (global and diffuse) levels, based on location.
The weather data available in the CIBSE guides are location specific but not site specific. The user should take under consideration that locality and microclimate can considerably affect design decisions. Local information could be acquired from city councils, local planning authorities, environment agency, met office etc.
As well as the solar and illuminance data, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change. For example, reduced cloud cover, especially during the summer, could exploit further the use of daylight and at the same time require further control of solar gains.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/)
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities, decisions will be made upon revising and further updating data in Guides A and J.
1.1.3. Weather data available for future climate conditions
At this pre-design stage of consulting with the client some general climate change statistics based on location could be used towards influencing the design brief in terms of climate change; possible impacts on building and building site and designing for future conditions.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” section 3 provides sunshine trends based on climate change data for the assessment of daylight and solar gains.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for future changes in cloud cover in order to assess trends in occurrence of solar radiation (global and diffuse) and illuminance (global and diffuse) levels, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The CIBSE climate change data (Guides A, J and TM34) are available for three locations only (London, Manchester and Edinburgh).
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides seasonal average cloud cover changes that could be used for daylight design. It should be noted that the cloud cover changes are assigned a higher uncertainty than for example the temperature and rainfall changes.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
1.1.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
1.1.5. Input from members
1.2. Identify client and building user needs and requirements
1.2.1. CIBSE guidance and tools
The building services engineers should be able to identify and acquire client requirements for lighting and daylight to be used while putting together the brief, so as to optimise design in terms of sustainability, energy efficiency, regulations, future needs etc. Such requirements could also include budget, required performance, attitude to risk, health and safety requirements etc.
An example of listing client and user needs and requirements is presented in CIBSE Knowledge Series publication KS8 “How to Design a Heating System”. Such a list could potentially be composed or customised by designers by using a series of CIBSE publications such as Guide A “Environmental Design” for internal environment requirements, Guide F “Energy Efficiency in Buildings” for energy efficiency requirements, Guide L “Sustainability”, Guide H “Building Control Systems” for control requirements etc.
CIBSE could offer a checklist of all relevant needs and requirements that the engineer could advise towards reaching objectives described in task 1.1.
1.2.2. Other useful references
Carbon Trust, “Energy Efficiency in Lighting – an Overview”, April 2003: http://http://www.cibse.org/pdfs/energylight.pdf.
The Society of Light and Lighting, “Lighting and the 2006 Building Regulations – Factfile No.9 2006”, April 2006: http://http://www.cibse.org/index.cfm?go=page.view&item=238.
1.2.3. Input from members
1.3. Refer to feedback and lessons learned from previous projects
1.3.1. CIBSE guidance and tools
The building services engineers should be able to keep in touch with previous projects in order to learn from them and improve their design methods. Some guidance on energy audits and surveys is included in Guide F, chapter 18.
Facilities managers (FMs) are usually responsible for the management of the building services and energy use in a building and have access to performance and energy use data. Liaising with the FMs during design process could provide useful information about the future operation and maintenance needs of a building and its services. Limited information on facilities and energy management is provided in Guide F, chapter 15.
Further guidance could include advice on possible channels and actions through which the design team could revisit or keep in touch with previous projects. Perhaps some research could be done in current practices.
Could CIBSE influence client perception of the value of monitoring and feedback? For example in some current projects monitoring and feedback is used as an educational process.
Further guidance could concentrate on encouraging integration with Facilities Management (FM), e.g. FM participation during design stages.
1.3.2. Other useful references
1.3.3. Input from members
1.4. Gather information about site, including utilities provision and fuel options
1.4.1. CIBSE guidance and tools
The building services engineers should make sure that they acquire all site specific information that could influence the design decisions.
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 4, §4.1) and CIBSE Guide L “Sustainability” (chapter 3, §3.1) provide information on site analysis for reducing energy demand in buildings.
A comprehensive checklist of all relevant site specific information and their possible sources e.g. city councils, local planning authorities, environment agency, met office, site visits etc. could help at this stage.
1.4.2. Weather data available for present climate conditions
At this pre-design stage of gathering site information, general daylight statistics based on location could influence decisions on building form and orientation.
CIBSE Guide A “Environmental Design” provides solar and illuminance data for various UK locations (chapter 2, §2.7) to inform the lighting strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides solar and illuminance data (chapter 5), for the same UK locations.
The user should be looking for present day statistics of occurrence of solar radiation (global and diffuse) and illuminance (global and diffuse) levels, based on location.
The weather data available in the CIBSE guides are location specific but not site specific. The user should take under consideration that locality and microclimate can considerably affect design decisions. Local information could be acquired from city councils, local planning authorities, environment agency, met office etc.
As well as the solar and illuminance data, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change. For example, reduced cloud cover, especially during the summer, could exploit further the use of daylight and at the same time require further control of solar gains.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating Guide J.
1.4.3. Weather data available for future climate conditions
At this pre-design stage of gathering site information, some general climate change statistics based on location could assist in understanding the changes that the site might undergo over the lifetime of the building. Such information could help in forming a flexible lighting strategy that could inspire future low/zero energy use for lighting.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” section 3 provides sunshine trends based on climate change data for the assessment of daylight and solar gains.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for future changes in cloud cover in order to assess trends in occurrence of solar radiation (global and diffuse) and illuminance (global and diffuse) levels, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The CIBSE climate change data (Guides A, J and TM34) are available for three locations only (London, Manchester and Edinburgh).
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides seasonal average cloud cover changes that could be used for daylight design. It should be noted that the cloud cover changes are assigned a higher uncertainty than for example the temperature and rainfall changes.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
1.4.4. Other useful references
Environment Agency’s Flood Map resource at: http://www.environment-agency.gov.uk/subjects/flood/826674/829803/
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: eca.knmi.nl
BRE (1990) “Climate and Site Development. Part 2: Influence of Microclimate”
BRE (1991) “Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice”
BRE (1992) “Site Layout for Sunlight and Solar Gain”
1.4.5. Input from members
1.5. Obtain information on use of building, occupancy hours and on possible building form, fabric, etc.
1.5.1. CIBSE guidance and tools
The building services engineers should be able to acquire all building related information such as form and fabric details, building use and occupancy patterns, etc. An example of listing building specific information is presented in the CIBSE Knowledge Series publication KS8 “How to Design a Heating System” (§ 3.2).
CIBSE could further develop a checklist and guidance on where/how to acquire the relevant information e.g. client’s brief, by further questioning the client, design plans and details, etc.
1.5.2. Other useful references
1.5.3. Input from members
1.6. Establish and confirm design requirements from Regulations, Codes of Practice etc.
1.6.1. CIBSE guidance and tools
The building services engineers should be able to refer to all regulations, codes and standards that relate to the individual project. The most up-to-date references and links to specific regulations and codes are included in CIBSE Guide L “Sustainability”. Legislation regarding health issues associated with the building services could also be found in CIBSE TM40 “Health Issues in Building Services”. Specific regulations for visual requirements could also be found in the SLL LG10 “Code for Lighting” and the CIBSE LG10 “Daylighting and Window Design”.
CIBSE could further develop a comprehensive and dynamic list of all necessary documents and where to find them, download them etc, as well as possible future developments and updates.
1.6.2. Other useful references
Carbon Trust, “Energy Efficiency in Lighting – an Overview”, April 2003: http://http://www.cibse.org/pdfs/energylight.pdf.
The Society of Light and Lighting, “Lighting and the 2006 Building Regulations – Factfile No.9 2006”, April 2006: http://http://www.cibse.org/index.cfm?go=page.view&item=238.
1.6.3. Input from members
1.7. Establish planning conditions for use of on-site renewables
1.7.1. CIBSE guidance and tools
The building services engineers should be able to establish requirements for the use of LZC technologies e.g. check infrastructure, financing, environmental impact, planning requirements etc. CIBSE Guide L “Sustainability” provides guidance on LZC technologies options, environmental impact, current government targets and cost. Further guidance on the requirements for the installation and operation of LZC technologies could also be found in AM12 “Small-Scale Combined Heat and Power for Buildings”, TM25 “Understanding Building Integrated Photovoltaics” and TM38 “Renewable Energy Sources for Buildings”.
Guidance on potential impact of future developments of the surrounding area that could affect the effectiveness of the LZC technologies – e.g. future high buildings will affect solar & daylight availability, change in land use could improve performance, etc. CIBSE could further develop a comprehensive and dynamic list of all relevant documents and/or where to find them e.g. county councils, building regulations, application documents, etc.
1.7.2. Other useful references
Grants available for installing renewables: http://www.clear-skies.org/
‘Integrating renewable energy into new developments: Toolkit for planners, developers and consultants’: http://www.london.gov.uk/mayor/environment/energy/london_renew.jsp
Energy Saving Trust: http://www.energysavingtrust.org.uk/generate_your_own_energy
1.7.3. Input from members
2. Preliminary Design
C. Concept
D. Design development
2.1. Establish the key design data and parameters that relate to the design of the lighting system, including building lighting requirements, and the potential use of renewables
2.1.1. CIBSE guidance and tools
The building services engineer should look for guidance on how to establish internal and external design conditions in order to inform the design of the lighting strategy e.g. visual comfort requirements, solar and illuminance weather data etc. Renewable energy could be considered here for providing the electricity for low energy electrical lighting.
CIBSE Guide A “Environmental Design” provides visual comfort criteria for lighting design (chapter 1, §1.8) and health issues associated with lighting (chapter 8, §8.5).
CIBSE TM40 “Health Issues in Building Services “ also provides comprehensive guidance on health issues associated with the operation and maintenance of building services.
The CIBSE Knowledge Series publication KS6 “Comfort” explains visual comfort criteria.
SLL “Code for Lighting” and CIBSE Lighting Guide LG10 “Daylight and Window Design” as well as the various CIBSE Lighting Guides for specific building application (e.g. industrial lighting, office lighting etc.) provide in depth guidance on lighting and daylight design criteria, visual comfort, required lighting levels for specific tasks etc.
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 5) and Guide L “Sustainability” (chapter 3, §3.1 and chapter 5, §5.1) provide general information on LZC technologies and design requirements.
Other CIBSE publications related to renewable technologies are the AM12 “Small-Scale Combined Heat and Power for Buildings”, TM25 “Understanding Building Integrated Photovoltaics and TM38 “Renewable Energy Sources for Buildings” with an accompanied simple tool to assist in initial identification of the most promising renewable sources for a given project.
The guidance is comprehensive in relation to lighting design criteria.
2.1.2. Weather data available for present climate conditions
Weather data at this preliminary design stage should be used to decide the external conditions for designing the lighting system. Data gathered at pre-design stage (task 1.4) could be further analysed based on building form and orientation, and with client involvement in order to establish external design conditions.
CIBSE Guide A “Environmental Design” provides solar and illuminance data for various UK locations (chapter 2, §2.7) to inform the lighting strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides solar and illuminance data (chapter 5), for the same UK locations.
Solar and wind data in Guide A (chapter 2, §2.7 and §2.8) and Guide J (chapter 5 and chapter 6) could also be used for assessing the potential use of renewables.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides maps of seasonal wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) and presented at a 5km x 5km resolution that could also be used for assessing the potential use of renewables. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The user should be looking for percentage of certain solar radiation and illuminance levels (global and diffuse) exceeded, as well as mean solar radiation and illuminance levels and sunshine duration, for different orientations and inclined surfaces, and different locations. Observed statistics of solar availability and wind speed could be used for assessing the potential of renewables.
As well as the solar and illuminance data, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change. For example, reduced cloud cover, especially during the summer, could exploit further the use of daylight and at the same time require further control of solar gains.
Site specific information should be acquired for assessing potential use of renewables e.g. local wind, sunshine availability and elements blocking the sun around the site etc. Local information could be acquired from city councils, local planning authorities, environment agency, met office etc. and by site visits and discussions with client.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating data in Guides A and J.
2.1.3. Weather data available for future climate conditions
Climate change information at this preliminary design stage should be used to decide on the external conditions for establishing the lighting strategy over the lifetime of the building. Data gathered at pre-design stage (task 1.4) could be analysed based on building form and orientation, and with client involvement in order to establish external design conditions that would incorporate climate change.
Climate change information could also be used here to inform future potential use of renewables; for example, examining the potential of powering the electrical lighting by the use of solar or wind power.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” section 3 provides sunshine trends based on climate change data for the assessment of daylight and solar gains.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain conditions exceeded in the future, such as certain solar radiation and illuminance levels (global and diffuse), as well as trends of mean solar radiation and illuminance levels, based on cloud cover, for different orientations and inclined surfaces, and different locations. Future trends of solar availability and wind speed could be used for assessing the potential of renewables.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
CIBSE climate change data are available for three locations only (London, Manchester and Edinburgh).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides seasonal average cloud cover changes that could be used for daylight design. It should be noted that the cloud cover changes are assigned a higher uncertainty than for example the temperature and rainfall changes. Furthermore, daily average wind speed and cloud cover changes in the UKCIP02 scientific report could also be used to assess potential use of renewables in the future.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.1.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
The Building Regulations second tier document “Low or Zero Carbon Energy Sources: Strategic Guide” provides a simplified calculation tool for assessing the reduction in carbon emissions through the use of LZC technology: http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_ZEROCARBONfinal.pdf
Geological surveys at the British Geological Survey: http://www.bgs.ac.uk/
Grants available for installing renewables: http://www.clear-skies.org/
“Integrating renewable energy into new developments: Toolkit for planners, developers and consultants”:
http://www.london.gov.uk/mayor/environment/energy/london_renew.jsp
Energy Saving Trust: http://www.energysavingtrust.org.uk/generate_your_own_energy
2.1.5. Input from members
2.2. Develop room design data sheets
2.2.1. CIBSE guidance and tools
The use of room data sheets (RDS) to define detailed performance requirements during design and specification of new build or refurbishment of buildings is common practice.
Such room data sheets were developed for the Carbon Trust’s Low Carbon Design Initiative (LCDI) to provide support to clients of the construction industry and their consultants/advisers, in developing design specifications for new building designs that will achieve a low carbon impact. Copies of the existing peer reviewed room data sheets, overarching technical briefing and other LCDI documents could be acquired from http://www.carbontrust.co.uk/about/reports/lcdi.
It should be noted that the above documents were originally intended to deal with school buildings, and their application to other building types should be undertaken with caution and additional client input.
Furthermore, the building services aspects of the LCDI room data sheets were mainly composed using the information in CIBSE guidance, e.g. CIBSE Guide A “Environmental Design”, SLL LG10 “Code for Lighting” and LG10 “Daylighting and Window Design”, and similarly the same guidance could be used to produce room data sheets for other building applications.
CIBSE could customise the above data sheets for use specifically by the building services engineers and for various types of buildings.
2.2.2. Other useful references
2.2.3. Input from members
2.3. Check that design parameters comply with legislation, energy targets etc.
2.3.1. CIBSE guidance and tools
Design parameters should be reviewed here to check that they comply with legislation and energy targets. A checklist of regulations, codes, standards etc, a sub category derived from the comprehensive list of task 1.6, could be used here that give specifications on design parameters and energy targets/benchmarks.
Guidance on ways to check the design is included in CIBSE Guide F “Energy Efficiency in Buildings”, chapter 13.
CIBSE could develop a dynamic list of possible documents to be used at this stage.
2.3.2. Other useful references
Carbon Trust, “Energy Efficiency in Lighting – an Overview”, April 2003: http://http://www.cibse.org/pdfs/energylight.pdf.
The Society of Light and Lighting, “Lighting and the 2006 Building Regulations – Factfile No.9 2006”, April 2006: http://http://www.cibse.org/index.cfm?go=page.view&item=238.
2.3.3. Input from members
2.4. Explore daylight/electric lighting relationship and develop control requirements
2.4.1. CIBSE guidance and tools
The building services engineer should look for guidance on zoning electric lighting in relation to daylight, based on occupancy patterns, building form and orientation. Rules of thumb could help in assessing the control requirements for managing the electric lighting/daylight relationship, based on occupancy, illuminance requirements and daylight availability and distribution. Early energy calculations could help identify optimum control solutions to optimise the use of daylight and achieve maximum energy savings .
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 4, §4.2.6) summarises the principles of zoning electric lighting in relation to daylight and explains the various lighting control options (chapter 9).
SLL “Code for Lighting” offers recommendations for electric lighting with daylight (§2.3) and choices of controls (§3.7), while CIBSE Lighting Guide LG10 “Daylight and Window Design” provides guidance on the integration of daylight and electric light, including control strategies and system options (§2.4).
The guidance is sufficient at this design stage.
2.4.2. Weather data available for present climate conditions
Weather data at this stage could inform of the availability of daylight based on location, orientation and time of year. Data gathered at pre-design stage (task 1.4) could be used here to investigate the relationship between electric lighting and daylight.
CIBSE Guide A “Environmental Design” provides illuminance data for various UK locations (chapter 2, §2.7.5) to inform the daylight availability. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides illuminance data (chapter 5.6), for the same UK locations.
The user should be looking for proportion of year, month and working day that certain illuminance levels (global and diffuse) are exceeded, for different locations.
As well as the illuminance data, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guide J do not include current manifestations of climate change. For example, reduced cloud cover, especially during the summer, could exploit further the use of daylight.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating data in Guides A and J.
2.4.3. Weather data available for future climate conditions
Climate change information at this preliminary design stage should be used to explore future relationships between electric lighting and daylight and future changes in the control requirements, over the lifetime of the building. Data gathered at pre-design stage (task 1.4) could also be used here.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” section 3 provides sunshine trends based on climate change data for the assessment of daylight and solar gains.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain illuminance levels (global and diffuse) exceeded for a proportion of year, month and working day, for different locations.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
CIBSE climate change data are available for three locations only (London, Manchester and Edinburgh).
The data available in the CIBSE Guides A, J and TM34 are general climate change trends that can inform towards future conditions, but can not be used readily in calculation tools.
The monthly changes of sunshine hours available in TM34 could in theory be added to the present day statistics, but some in-house expertise might be required.
Similarly, the UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides seasonal average cloud cover changes that could be used for daylight assessment. It should be noted that the cloud cover changes are assigned a higher uncertainty than for example the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.4.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
BRE (2002) “Control of Solar Shading”
BRE (2002) “Selecting Lighting Controls”
BRE (1984) “A New Method for Predicting Energy Saving from on/off Photoelectric Controls”
2.4.5. Input from members
2.5. Assess requirements for glare and solar gain control
2.5.1. CIBSE guidance and tools
The building services engineer should look for guidance and tools for assessing various glazing and shading options in order to control glare and solar gains, based on occupancy patterns, building form and orientation.
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 4, §4.2.6) summarises the principles of solar control and offers various shading options.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows (§2.2.2.2) and provides guidance on the choice of glazing and shading options (§2.3).
CIBSE TM37 “Design for Improved Solar Shading Control” provides extensive guidance on the control of glare and solar gains. Tools are provided for the calculation of solar gains and internal lighting gains, and for the analysis of the thermal and lighting performance of various shading techniques as well as the performance of various glazing and shading combinations.
CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” provides guidance on the control of solar gains and glare by presenting various glazing and shading options for highly glazed buildings.
The guidance is sufficient at this design stage.
2.5.2. Weather data available for present climate conditions
Weather data at this stage could be used to assess the thermal and lighting performance of various glazing and shading control strategies based on location, orientation and time of year. External design conditions established at pre-design stage (task 1.4) could be used here.
CIBSE Guide A “Environmental Design” provides solar and illuminance data for various UK locations (chapter 2, §2.7) to inform the lighting strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides solar and illuminance data (chapter 5), for the same UK locations.
The user should be looking for proportion of year, month and working day that certain solar radiation and illuminance levels (global and diffuse) are exceeded, for different locations.
As well as the solar and illuminance data, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change. For example, reduced cloud cover, especially during the summer, could exploit further the use of daylight and at the same time require further control of solar gains.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating data in Guides A and J.
2.5.3. Weather data available for future climate conditions
Climate change information at this design stage should be used to explore future requirements for glare and solar gain control, over the lifetime of the building. External design conditions established at pre-design stage (task 1.4) could also be used here.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” section 3 provides sunshine trends based on climate change data for the assessment of daylight and solar gains.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain solar radiation and illuminance levels (global and diffuse) exceeded for a proportion of year, month and working day, for different locations.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
CIBSE climate change data are available for three locations only (London, Manchester and Edinburgh).
The data available in the CIBSE Guides A, J and TM34 are general climate change trends that can inform towards future conditions, but can not be used readily in calculation tools.
The monthly changes of sunshine hours available in TM34 could in theory be added to the present day statistics, but some in-house expertise might be required.
Similarly, the UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides seasonal average cloud cover changes that could be used for daylight assessment. It should be noted that the cloud cover changes are assigned a higher uncertainty than for example the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.5.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
BRE (2002) “Control of Solar Shading”
BRE (2002) “Selecting Lighting Controls”
BRE (1984) “A New Method for Predicting Energy Saving from on/off Photoelectric Controls”
BRE (1999) “Solar Shading of Buildings”
BRE (2004) “Impact of Horizontal Shading Devices on Peak Solar Gains through Windows”
BRE (2005) “Summertime Solar Performance of Windows with Shading Devices”
2.5.5. Input from members
2.6. Examine interactions with other services
2.6.1. CIBSE guidance and tools
The building services engineer should examine possible interactions of the lighting strategy with other services. Such interactions should include internal heat gains from lighting when calculating the heating and cooling loads, the effect of solar control on the natural ventilation flow, etc.
A model for calculating heat gains from lighting in included in CIBSE Guide A “Environmental Design”, chapter 5.
A checklist of possible interactions of the lighting strategy with other systems and links to relevant guidance could be useful at this point.
2.6.2. Other useful references
2.6.3. Input from members
2.7. Consider zoning requirements
2.7.1. CIBSE guidance and tools
Appropriate zoning of spaces based on orientation, percentage of glazing, activity and hours of operation, etc. could help in maximising the daylight availability and the efficiency of the lighting system. The building services engineers should be able to identify zoning requirements and integrate them into the design of the systems.
Guidance in the SLL LG10 “Code for Lighting” (chapter 3) and the CIBSE LG10 “Daylighting and Window Design” (chapter 2) could be used to inform zoning of the space based on daylight availability and illuminance requirements.
More in-depth and specialised guidance is needed to inform effective zoning that could optimize the efficiency of the lighting strategy.
2.7.2. Other useful references
Carbon Trust, “Energy Efficiency in Lighting – an Overview”, April 2003: http://http://www.cibse.org/pdfs/energylight.pdf.
The Society of Light and Lighting, “Lighting and the 2006 Building Regulations – Factfile No.9 2006”, April 2006: http://http://www.cibse.org/index.cfm?go=page.view&item=238.
2.7.3. Input from members
2.8. Consider lighting system options and equipment
2.8.1. CIBSE guidance and tools
The building services engineer should be using guidance on the different types of lighting; general, localised, task lighting, display lighting etc, based on application, and possible obstructions. Furthermore, guidance on available equipment and their properties, such as lumen output, life expectancy, and aesthetics, should also be considered here.
Guidance on lighting systems and equipment could be found in CIBSE Guide F “Energy Efficiency in Buildings”, chapter 9, SLL LG10 “Code for Lighting”, and the rest of LG publications for specific building applications (e.g. LG01 “Industrial Lighting”, LG02 “Hospitals and Health Care Buildings” etc.).
Guidance seems sufficient at this design stage.
2.8.2. Other useful references
Carbon Trust, “Energy Efficiency in Lighting – an Overview”, April 2003: http://http://www.cibse.org/pdfs/energylight.pdf.
2.8.3. Input from members
2.9. Establish contribution from renewable sources
2.9.1. CIBSE guidance and tools
Renewable energy could be considered here for providing the electricity for low energy electrical lighting.
The building services engineer should look for guidance and calculation tools to assess the potential use of renewable energy sources based on the building form, application and location. Cost and benefit analysis is essential at this point as well as assessing potential sources of financing the technologies, environmental impact and alternatives. Site and building data gathered during pre-design stage as well as key design parameters from task 2.1 should also be used here.
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 5) and Guide L “Sustainability” (chapter 3, §3.1 and chapter 5, §5.1) provide general information on LZC technologies and design requirements.
Other CIBSE publications related to renewable technologies are the AM12 “Small-Scale Combined Heat and Power for Buildings”, TM25 “Understanding Building Integrated Photovoltaics and TM38 “Renewable Energy Sources for Buildings” with an accompanied simple tool to assist in initial identification of the most promising renewable sources for a given project.
CIBSE is not offering at the moment a calculation tool for the analysis of contribution from renewable energy sources and LZC technologies. It is an opportunity for CIBSE to develop a calculation tool that would provide a quantitative analysis of the potential use of such technologies as well as a cost and benefit analysis, for specific projects.
2.9.2. Weather data available for present climate conditions
At this preliminary design stage a good knowledge of the site and the microclimate is essential towards analysing the potential of various renewable resources.
CIBSE Guide A “Environmental Design” (chapter 2, §2.7 and §2.8) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapters 5 and 6) provide solar and wind data, for various UK locations, that could be used for assessing potential use of renewables.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides wind speed trends based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The user should be looking for site specific weather data and local elements that could potentially affect the microclimate and/or the performance of renewable technologies.
The data in Guides A and J are not at the moment consistent. Wind data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1975-1994). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of unlike external design conditions than those currently occurring.
The CIBSE weather data are location specific but not site specific. Site specific information should be acquired for assessing potential use of renewables e.g. local wind, sunshine availability and elements blocking the sun around the site etc. Local information could be acquired from city councils, local planning authorities, environment agency, Met office etc. and by site visits and discussions with client.
Guidance is required on the type of weather information needed for assessing potential of renewables and how to obtain such site specific information, e.g. Met Office, local weather station, city council archives etc.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
2.9.3. Weather data available for future climate conditions
At this preliminary design stage a good understanding of the future weather trends and the microclimate of the site could help towards forming a strategy for improving the building’s carbon emissions by incorporating more LZC technologies.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide future changes in sunshine hours but not wind data.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain weather variables changing in the future that could potentially affect the performance of renewable technologies. For example increase sunshine hours will increase the use of solar renewable technologies.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Changes in sunshine hours included in TM34 could be used towards assessing future use of renewables, but there are no wind data available for wind technologies due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed and cloud cover changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of available sources of weather data suitable for calculating the future potential of renewable sources of energy and other LZC technologies should be made available and be incorporated in the weather related CIBSE guidance.
2.9.4. Other useful references
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
The Building Regulations second tier document “Low or Zero Carbon Energy Sources: Strategic Guide” provides a simplified calculation tool for assessing the reduction in carbon emissions through the use of LZC technology: http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_ZEROCARBONfinal.pdf
Geological surveys at the British Geological Survey: http://www.bgs.ac.uk/
Grants available for installing renewables: http://www.clear-skies.org/
‘Integrating renewable energy into new developments: Toolkit for planners, developers and consultants’:
http://www.london.gov.uk/mayor/environment/energy/london_renew.jsp
Energy Saving Trust: http://www.energysavingtrust.org.uk/generate_your_own_energy
2.9.5. Input from members
2.10. Consider operating, maintenance and control strategies, and building usage and layout data
2.10.1. CIBSE guidance and tools
The building services engineers should investigate the various control, maintenance and operating strategy options based on the lighting strategy under consideration. A checklist of information required, e.g. building plans, space usage, visual comfort requirements etc, could be used here to inform the process.
CIBSE guidance on lighting controls exists in Guide H “Building Control Systems” (§5.15), Knowledge Series KS4 “Understanding Controls”, Guide F “Energy Efficiency in Buildings” (chapter 9) and SLL LG10 “Code for Lighting” (§2.4). The “Code for Lighting” also includes guidance on the maintenance of lighting systems and a formula for calculating the maintenance factor (§3.8.2).
CIBSE Guide M “Maintenance Engineering and Management” also provides comprehensive guidance in the management, operation, maintenance and control of building services including the lighting system. Guide F Part B refers to management (chapter 15) and maintenance of building services (chapter 17), while the principles of building services management are analysed in the Knowledge Series publication KS5 “Making Buildings Work”.
CIBSE could provide a checklist of all requirements necessary for designing the control, maintenance and operation strategy of the lighting system.
2.10.2. Other useful references
2.10.3. Input from members
2.11. Assess options against client requirements, performance, risk, energy use etc.
2.11.1. CIBSE guidance and tools
The building services engineers should be able to follow a methodology for assessing the various options against a series of criteria set by the client, building regulations, standards etc. The assessment methods could include a series of consultations with the design team and the client, a prioritising strategy based on client’s brief etc. Assessing the various options identified could become critical when choosing between similar options.
CIBSE could provide a methodology for assessing options.
2.11.2. Other useful references
2.11.3. Input from members
2.12. Select proposed system
2.12.1. CIBSE guidance and tools
Based on the assessment of various options during task 2.11 the building services engineers should be able to identify the optimum solution based on client brief.
See task 2.11
2.12.2. Other useful references
2.12.3. Input from members
3. Design Development
E. Technical design
3.1. Calculate daylight availability and distribution
3.1.1. CIBSE guidance and tools
The building services engineer should be looking for tools, manual and computer based, to calculate the daylight availability and distribution based on building form and orientation, location, time of year. Guidance on window design could also be used here.
CIBSE Lighting Guide LG10 “Daylight and Window Design” provides guidance and manual tools for the assessment of daylight availability and window design, sizing and positioning. Furthermore, section 3 of the same guide provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
Some guidance on daylight analysis could also be found in SLL “Code for Lighting” section 3.4.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space daylight distribution (model output) by changing shading options (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.1.2. Weather data available for present climate conditions
Weather data at this stage could analyse the availability and distribution of daylight based on window position and size, building location and orientation and time of year. Site specific elements that could affect the daylight availability and distribution should also be analysed here as detailed as possible.
CIBSE Guide A “Environmental Design” provides illuminance data for various UK locations (chapter 2, §2.7.5) to inform the daylight availability and distribution. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides illuminance data (chapter 5.6), for the same UK locations.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For manual calculations the user should be looking for proportion of year, month and working day that certain illuminance levels (global and diffuse) are exceeded, for different locations.
As well as the illuminance data, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guide J do not include current manifestations of climate change. For example, reduced cloud cover, especially during the summer, could exploit further the use of daylight.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain weather events, e.g. once in x observed years event of monthly illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating data in Guides A and J.
3.1.3. Weather data available for future climate conditions
Climate change information at this design stage could be used to explore future daylight availability, over the lifetime of the building.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” section 3 provides sunshine trends based on climate change data for the assessment of daylight and solar gains.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For manual calculations the user should be looking for probability of certain illuminance levels (global and diffuse) exceeded for a proportion of year, month and working day, for different locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain weather events, e.g. probability of certain monthly proportion of illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
CIBSE climate change data are available for three locations only (London, Manchester and Edinburgh).
The data available in the CIBSE Guides A, J and TM34 are general climate change trends that can inform towards future conditions, but can not be used readily in calculation tools.
The monthly changes of sunshine hours available in TM34 could in theory be added to the present day statistics, but some in-house expertise might be required.
Similarly, the UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides seasonal average cloud cover changes that could be used for daylight assessment. It should be noted that the cloud cover changes are assigned a higher uncertainty than for example the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.1.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
BRE (1996) “Designing with Innovative Daylighting”
3.1.5. Input from members
3.2. Assess potential conflict between daylight and thermal performance of space and establish glare and solar gain control strategy
3.2.1. CIBSE guidance and tools
The building services engineer should be looking for advanced tools to assess the relationship between daylight and thermal performance of space; examine conflict areas and identify possible solutions towards achieving both thermal and visual comfort.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows (§2.2.2.2) and provides guidance on the choice of glazing and shading options (§2.3). Furthermore, section 3 of the same guide provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
CIBSE TM37 “Design for Improved Solar Shading Control” provides extensive guidance on the control of glare and solar gains, while CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” provides guidance on the control of solar gains and glare by presenting various glazing and shading options for highly glazed buildings. The same publication includes a simple computer based tool called “Façade Selector” which allows designers to specify basic façade requirements such as peak heating/cooling loads, daylight availability, orientation and cost, in order to identify the façade system that will meet these requirements.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space temperatures (model output) by changing shading options (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.2.2. Weather data available for present climate conditions
Weather data at this stage could be used to examine the relationship between the lighting and thermal performance of space and assess the dynamic performance of various glazing and shading control strategies by the use of hourly external data.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.2.3. Weather data available for future climate conditions
Climate change hourly information could be used at this design stage to explore future dynamic relationships between the thermal and daylight performance of space and explore future requirements for glare and solar gain control, over the lifetime of the building.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.2.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
BRE (1999) “Solar Shading of Buildings”
BRE (2004) “Impact of Horizontal Shading Devices on Peak Solar Gains through Windows”
BRE (2005) “Summertime Solar Performance of Windows with Shading Devices”
3.2.5. Input from members
3.3. Electric lighting - calculations
3.3.1. CIBSE guidance and tools
Where the need for electric lighting has been identified, calculations should determine the luminaires required to achieve illuminance levels, based on application and daylight analysis.
At this stage the lighting engineer should also consider a control strategy for energy saving.
The SLL LG10 “Code for Lighting” (§3.8) presents a model for the calculation of luminaires necessary to obtain the required illuminance levels. The same guide, chapter 2, also includes illuminance levels for specified applications.
CIBSE guidance on lighting controls in order to achieve energy efficiency exists in Guide H “Building Control Systems” (§5.15), Knowledge Series KS4 “Understanding Controls”, Guide F “Energy Efficiency in Buildings” (chapter 9) and SLL LG10 “Code for Lighting” (§2.4).
Guidance seems sufficient.
3.3.2. Other useful references
3.3.3. Input from members
3.4. Check system selection provision still appropriate
3.4.1. CIBSE guidance and tools
The building services engineers should be using assessment methods to evaluate the option selected at task 2.12. The evaluation should be based on results from detailed calculations performed in the previous tasks of stage 3.
CIBSE could provide a checklist of criteria for the evaluation of selected systems.
3.4.2. Other useful references
3.4.3. Input from members
3.5. Consider lighting source positions and interactions
3.5.1. CIBSE guidance and tools
The building services engineers should be using guidance on the positioning of light sources, based on application, and the various choices available.
Guidance on the specification and interaction of illuminance variation could be found in the SLL LG10 “Code for Lighting” (§3.8).
CIBSE could develop guidance on the various types of luminaires available and their suitability in various types of applications.
3.5.2. Other useful references
Carbon Trust, “Energy Efficiency in Lighting – an Overview”, April 2003: http://http://www.cibse.org/pdfs/energylight.pdf.
3.5.3. Input from members
3.6. Consider mounting and electricity supply
3.6.1. CIBSE guidance and tools
The building services engineers should be using guidance on lighting circuit wiring, voltage distribution, power generation, earthing etc. Also guidance on sizing the mains, electricity supply from grid and/or from renewables, as well as health and safety issues associated, could also be used here.
CIBSE Guide K “Electricity in Buildings” covers the above issues of electricity generation and supply, wiring etc.
The guidance on electrical services could be updated to include design issues associated with electricity generation from renewable sources.
3.6.2. Other useful references
3.6.3. Input from members
3.7. Develop maintenance requirements
3.7.1. CIBSE guidance and tools
Data gathered at task 2.10 could be used here to determine maintenance schedule of lighting sources to maintain required performance. Guidance on possible maintenance problems/issues, e.g. external shading devices could cause problems in the process of cleaning windows, health and safety issues etc. could also be used here.
The SLL publication LG10 “Code for Lighting” includes guidance on the maintenance of lighting systems and a formula for calculating the maintenance factor (§3.8.2).
Furthermore, CIBSE Guide M “Maintenance Engineering and Management” provides guidance on the maintenance strategies of building services including the lighting system. Guide F “Energy Efficiency in Buildings” Part B also refers to the maintenance of building services (chapter 17).
Existing guidance seems sufficient.
3.7.2. Other useful references
3.7.3. Input from members
3.8. Size and select lighting equipment and distribution network and determine any distribution losses
3.8.1. CIBSE guidance and tools
Based on the outcomes of tasks 3.5 and 3.6 the building services engineers should be able to size and select the lighting sources and complete the design of the lighting wiring circuit.
The guidance in CIBSE Guide F “Energy Efficiency in Buildings”, chapter 9, SLL LG10 “Code for Lighting”, and the other specific application LG guides (e.g. LG01 Industrial Lighting etc.), could be a useful reference in relation to the choice of lighting systems based on application.
CIBSE Guide K “Electricity in Buildings” provides guidance on electricity generation and supply, wiring etc.
See notes in tasks 3.5 and 3.6
3.8.2. Other useful references
3.8.3. Input from members
3.9. Analyse lighting diversity and determine the overall control strategy
3.9.1. CIBSE guidance and tools
The building services engineer should be looking for advanced tools to examine the overall lighting performance (daylight and electric) and establish the overall control strategy. Part of the analysis could concentrate on identifying optimum control solutions to optimise the use of daylight and achieve maximum energy savings.
Conclusions from tasks 3.1 and 3.2, where daylight and relationship between thermal and lighting performance were analysed, should also be taken under consideration.
SLL “Code for Lighting” offers choices of controls (§3.7), while CIBSE Lighting Guide LG10 “Daylight and Window Design” provides guidance on the integration of daylight and electric light, including control strategies and system options (§2.4).
Computer tools should be used here to analyse the lighting diversity and interaction between daylight and electric lighting.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows, section 3, provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” demonstrates the use of computer tools to undertake a lighting analysis, for a case study.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space lighting diversity (model output) by changing the control settings (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.9.2. Weather data available for present climate conditions
Weather data at this stage could be used to examine the lighting diversity based on the relationship between the daylight and electric lighting establish the control strategy for maintaining desirable lighting levels and visual comfort.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.9.3. Weather data available for future climate conditions
Climate change hourly information could be used at this design stage to explore future dynamic relationships between daylight and electric lighting and explore future control requirements, over the lifetime of the building.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.9.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
BRE (2002) “Control of Solar Shading”
BRE (2002) “Selecting Lighting Controls”
BRE (1984) “A New Method for Predicting Energy Saving from on/off Photoelectric Controls”
BRE (1999) “Solar Shading of Buildings”
BRE (2004) “Impact of Horizontal Shading Devices on Peak Solar Gains through Windows”
BRE (2005) “Summertime Solar Performance of Windows with Shading Devices”
3.9.5. Input from members
3.10. Calculate electricity loads
3.10.1. CIBSE guidance and tools
The building services engineers should be able to calculate the electricity loads and load variation for lighting, at this stage. CIBSE Guide K “Electricity in Buildings” provides guidance and tools for the calculation of electricity loads.
Existing guidance seems sufficient.
3.10.2. Other useful references
3.10.3. Input from members
3.11. Determine interactions with other services
3.11.1. CIBSE guidance and tools
The building services engineer should be looking for advanced tools to examine the interactions between the lighting and other services, e.g. solar gains and internal heat gains for heating, cooling and ventilation services design, electric load for electrical services design etc. A list of all possible interactions would have been composed during task 2.6. Conclusions from task 3.2 could also be used here.
Computer tools could be used here to analyse the relationships between lighting and other services.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space temperatures (model output) by changing daylight and electric lighting patterns (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.11.2. Weather data available for present climate conditions
Weather data at this design stage could be used to examine the interactions between the lighting strategy and other services.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.11.3. Weather data available for future climate conditions
Climate change hourly information could be used at this design stage to explore future dynamic interactions between lighting and other services, over the lifetime of the building, e.g. reduction of energy demand for electric lighting (and resulted heat gains), but increase of cooling demand due to high solar gains.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.11.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
BRE (1999) “Solar Shading of Buildings”
BRE (2004) “Impact of Horizontal Shading Devices on Peak Solar Gains through Windows”
BRE (2005) “Summertime Solar Performance of Windows with Shading Devices”
3.11.5. Input from members
3.12. Consider any standby and future requirement
3.12.1. CIBSE guidance and tools
The building services engineers should be using guidance on issues related to assessing standby and future lighting requirements, e.g. when flexibility is required in the way the space is lit, possible future uses of space, etc.
Guidance is needed on standby and future requirements when sizing and selecting the lighting system, especially when integration with other systems is under consideration, e.g. chilled ceilings with integrated lighting structure.
3.12.2. Other useful references
3.12.3. Input from members
3.13. Size and select the mains
3.13.1. CIBSE guidance and tools
The lighting system should be considered when sizing and selecting the mains. This topic is covered in length by the “Electrical” section of the “Design Compass”.
CIBSE Guide K “Electricity in Buildings” provides guidance for the design of the electrical systems, including the lighting system, in buildings.
The guidance on electrical services could be updated to include design issues associated with electricity generation from renewable sources.
3.13.2. Other useful references
3.13.3. Input from members
3.14. Check layouts and services co-ordination for clashes and ease of commissioning and maintenance
3.14.1. CIBSE guidance and tools
Guidance and outcomes from tasks 3.5 – 3.8 could be used here in order to check lighting system layout, while results from tasks 3.2, 3.9 and 3.11 would have identified possible areas of conflict of services. Dynamic simulation tools could also be used in order to check coordination of systems and avoid conflict of services e.g. possible conflict between solar gain control and daylight levels in the room etc.
Comprehensive guidance on commissioning and maintenance can be found in CIBSE “Guide to Ownership, Operation and Maintenance of Building Services” and Guide M “Maintenance Engineering and Management”. CIBSE Commissioning Codes L “Lighting” and C “Automatic Controls” concentrate on comissioning issues relative to the respective systems.
CIBSE Guide F “Energy Efficiency in Buildings” provides guidance on the commissioning process (chapter 14) and maintenance issues (chapter 17) in order to achieve expected efficiency.
Computer based simulation tools, could be used to check co-ordination and clashes of services, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine whether daylight and electric lighting are operating at the same time (model output) by changing shading strategy (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.14.2. Weather data available for present climate conditions
Co-ordination of building services is important for energy efficiency and cutting carbon emissions, and for cost effectiveness of systems operation. A detailed analysis of the systems’ operation can point out the areas where possible clashes of services could exist, for example shut blinds at west/east window, to avoid direct sunlight and solar gains, and electric lighting in operation.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects examine the use of UKCIP08 climate change information in building design.
3.14.3. Weather data available for future climate conditions
Future climate change conditions could alter the relationships between services and the maintenance strategy of the systems. A detailed analysis of the future operation of the systems could help identifying changes in operation and maintenance and incorporate solutions in the long term operational strategy of the building.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.14.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
3.14.5. Input from members
3.15. Review system design and check predicted system performance
3.15.1. CIBSE guidance and tools
At this advanced design stage a review of the overall system design against targets and client requirements could concentrate on various aspects of the design intent such as achieving required performance, energy efficiency at part load and control performance. This task will concentrate on confirming that the energy targets and the internal visual comfort requirements are met.
Computer tools should be used to review system design and check system performance based on hourly external data and corresponding building performance.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows, section 3, provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” demonstrates the use of computer tools to undertake a lighting analysis, for a case study.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example confirm that the expected energy use for lighting meets targets (model output) for variable occupancy patterns (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.15.2. Weather data available for present climate conditions
At this advanced design stage a detailed analysis of the lighting strategy performance is essential for the fine tuning of the design. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic lighting and thermal performance of the building. Extreme and average weather conditions should be used to examine the system performance and associated energy use.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.15.3. Weather data available for future climate conditions
At this advanced design stage the designer should explore future performance of the lighting strategy to inform plans for further development towards lower building energy use and carbon emissions, e.g. predicted reductions in cloud cover may in some cases decrease energy use for lighting. A detailed analysis of system future performance is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Extreme and average weather conditions should be used to examine future system performance and associated energy use.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.15.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
3.15.5. Input from members
3.16. Check part load performance of electric lighting system
3.16.1. CIBSE guidance and tools
At this advanced design stage a review of the overall system design against targets and client requirements could concentrate on various aspects of the design intent such as achieving required performance, energy efficiency at part load and performance of controls. This task will concentrate on confirming that the system efficiency targets and system performance requirements are met at part load.
Often systems operate at high efficiency at peak load and low efficiency at part load. The lighting diversity analysis in task 3.9 could identify integrated solutions for lighting for example a combination of daylight and LZC technologies to power low energy lighting.
Computer tools should be used to check that lighting requirements are met at all times, and energy efficiency targets are met at part load.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows, section 3, provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” demonstrates the use of computer tools to undertake a lighting analysis, for a case study.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine lighting variation (model output) for variable sky illuminance (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.16.2. Weather data available for present climate conditions
The systems’ performance will often be directly associated with external conditions. It is important that the designer is able to check that the lighting strategy will cover low and high demand without compromising its efficiency. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Particular weather conditions (e.g. variable sky illuminance) could be identified in order to check system performance and associated energy use.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.16.3. Weather data available for future climate conditions
Conclusions on the performance of the lighting strategy based on future conditions could help identify the potential of improving energy use for lighting. It is increasingly part of the client’s brief to present options for a future zero or neutral carbon building, so it is important that the designer is able to examine further options. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. The system variable load performance could be examined for future weather events in order to identify future options e.g. cover electric lighting requirements with a combination of LZC technologies.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance.
3.16.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
3.16.5. Input from members
3.17. Check that the selected controls are capable of achieving the required level of control, response and energy efficiency, particularly at part load
3.17.1. CIBSE guidance and tools
At this advanced design stage a review of the overall system design against targets and client requirements could concentrate on various aspects of the design intent such as achieving required performance, energy efficiency at part load and performance of controls. This task will concentrate on confirming that the controls are able to respond effectively to the changes in the internal environment without compromising energy efficiency. Part of this task could be confirming that the selected control strategy is optimising the use of daylight and achieving maximum energy savings.
The lighting diversity analysis in task 3.9 could identify integrated solutions for lighting for example a combination of daylight and LZC technologies to power low energy lighting. Lighting and solar controls will need to be fine tuned in order to cover variable lighting demand without compromising thermal performance of space.
Computer tools should be used to check that lighting requirements are met at all times, and energy efficiency targets are met at part load.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows, section 3, provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” demonstrates the use of computer tools to undertake a lighting analysis, for a case study.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine lighting variation (model output) for variable solar control (model input). Suggested sensitivity analysis could vary based on building/space application and layout, façade/window orientation, e.g. different for south and north facing spaces, office and industrial space etc.
3.17.2. Weather data available for present climate conditions
The ability of the controls to respond effectively to internal thermal and visual conditions and part load performance of the systems is essential for the efficient operation of the lighting strategy. It is important that the designer is able to check that the system will respond effectively to variable lighting demand without compromising thermal performance of the space. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Particular weather conditions (e.g. variable sky illuminance) could be identified in order to check system performance and associated energy use.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.17.3. Weather data available for future climate conditions
Conclusions on the ability of the controls to respond effectively to variable demand, based on future conditions, could help identify future requirements for the fine tuning of controls. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. The response of the controls to the system’s variable performance could be examined for future weather events in order to identify future control requirements.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.17.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
3.17.5. Input from members
3.18. Check that final system and components meet client requirements for performance, quality, reliability, etc at acceptable cost; and also meet required energy targets and comply with regulations, such as meeting the seasonal efficiency requirements
3.18.1. CIBSE guidance and tools
This task confirms that the final solution does meet original design objectives. Actions could include value engineering and confirming compliance with the building regulations.
Building services engineers should be looking for guidance on value engineering and building regulations compliance tools. They should also make sure that there are no major alterations in the building’s envelope that have been done by the design team to affect building performance.
Computer based simulation tools should be used here to check overall building performance and compliance with the building regulations, based on hourly external data. Results from simulations completed during previous tasks could also be used here.
CIBSE Lighting Guide LG10 “Daylight and Window Design” explains the thermal impact of windows, section 3, provides guidance on the use of computer based tools for daylight calculations, as well as the use of scale model tools such as artificial skies.
CIBSE TM35 “Environmental Performance Toolkit for Glazed Facades” demonstrates the use of computer tools to undertake a lighting analysis, for a case study.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of computer models. SLL TM28 “Benchmarking Lighting Design Software” provides measured illuminance data of representative lighting installations to enable the measured data to be used as a benchmark data set for lighting design software (available free of charge to members via the CIBSE website). CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
CIBSE could provide guidance on how to complete a value engineering assessment and issues associated. Guidance on SBEM and the other accredited compliance tools could inform the designers of the ‘problem areas’ related to the use of each of the tools. Finally, checklists of possible areas where last minute changes, e.g. by completing a value engineering assessment, could affect the building performance, could be beneficial towards maintaining performance of design intent.
3.18.2. Weather data available for present climate conditions
Building Regulations require the use of certified computer tools in order to prove compliance. The above requirement is also part of the European Energy Performance of Buildings Directive. Such tools use hourly weather data to provide information on the energy use and associated carbon emissions of the building and as a result provide evidence of the building’s design intent compliance with the building regulations.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
The CIBSE Test Reference Years (TRY) are hourly weather series that include solar radiation and cloud cover data over a year and are available for 14 different UK locations.
The CIBSE Design Summer Years (DSY) are hourly weather series that include solar radiation and cloud cover data over the period April – September and are available for the same 14 UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. once in x observed years event of monthly solar radiation and illuminance levels.
The TRYs and DSYs have been specifically composed for energy and overheating assessments respectively and are not necessarily appropriate for lighting design. Details on the selection criteria of TRYs and DSYs can be found in (Guide J, chapter 8).
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to also present past events based on observed data in a probabilistic way (http://www.ukcip08.net/).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net/).
There are currently discussions that explore the ways to use future weather data, rather than present data based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options (including the use of the forthcoming UKCIP08 information) of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of UKCIP08 climate change information in building design.
3.18.3. Weather data available for future climate conditions
Even though not formally required by the Building Regulations it is increasingly part of the client’s brief to show that the building will be able to maintain predicted energy performance over its lifetime. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic energy performance of the building in response to external conditions. Such tools use hourly weather data to provide information on the energy use and associated carbon emissions of the building and as a result provide evidence of the building’s long term energy performance based on design intent.
Integrated computer tools that calculate thermal, ventilation (CFD) and lighting performance could be used here. They often use the same hourly weather series to express external conditions, for all three applications, which may not provide fully optimised solutions.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal (http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of certain solar radiation and illuminance (global and diffuse on a surface) levels, e.g. probability of certain monthly proportion of solar radiation and illuminance levels happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.18.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
3.18.5. Input from members
4. Pre-Construction
F. Production information
G. Tender documentation
H. Tender action
4.1. Information from Deisgn Development to be used here
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4.2. CIBSE members’ involvement at this stage depends on the individual contract with the client
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5. Construction
J. Mobilisation
K. Construction to practical completion
5.1. CIBSE members’ involvement at this stage depends on the individual contract with the client
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6. Post Completion
L. Post practical completion
6.1. Commissioning, management and maintenance of the lighting system
6.1.1. CIBSE guidance and tools
Guidance on the commissioning, management and maintenance of the building services, after the completion of the project, could be used here by facilities and energy managers in order to meet the design specifications.
The CIBSE/SLL Commissioning Code L “Lighting” could be used here to inform the commissioning process of the lighting system. CIBSE Guide M “Maintenance Engineering and Management” provide guidance on the management and maintenance of the building services.
CIBSE guidance seems sufficient.
6.1.2. Other useful references
6.1.3. Input from members
6.2. Design review – Refer to feedback and lessons learned
6.2.1. CIBSE guidance and tools
The building services engineers should be able to keep in touch with previous projects in order to learn from them and improve their design methods.
For post occupancy reviews see energy audits and surveys in Guide F “Energy Efficiency in Buildings”, chapter 18.
CIBSE could offer guidance on reviews at design stage (project team meetings, reviews with other design teams etc) and reviewing system performance at post occupancy.
Further guidance could include advice on possible channels and actions through which the design team could revisit or keep in touch with previous projects. Perhaps some research could be done in current practices.
Could CIBSE influence client perception of the value of monitoring and feedback? In some current projects monitoring and feedback is used as educational process.
Encourage integration with Facilities Management (FM), e.g. develop processes of reporting to the design team.
6.2.2. Other useful references
6.2.3. Input from members
6.3. End of life
6.3.1. CIBSE guidance and tools
Guidance on the building demolition and the recycling of materials is relevant here.
CIBSE Guide L “Sustainability”, chapter 8, provides some guidance on this last stage of the building’s life.
Further guidance is needed on end of life stage.
6.3.2. Other useful references
6.3.3. Input from members