This project will develop sound methods for future climate change data for building designers to use for new buildings and refurbishments that could last to the end of this century. The principal application output will be a draft Technical Memorandum (TM) for the Chartered Institution of Building Services Engineers, CIBSE, suitable for practising designers. This will be supported by extensive case studies to validate the new weather data design methodology and be used in research tasks described later. 'Story lines' relevant to different scenarios for the climate and built environment will be developed as well as risk levels in building design to enable designers to use the weather data with confidence. The TM will provide CIBSE with a consistent methodology for the selection and use of future data for its new Design Guide, a fundamental document used by designers of buildings and their services and a supporting document for the Government's Building Regulations. The basis for this project will be the UK Climate Impacts Programme (UKCIP) future scenarios to be published in 2008 (UKCIP08) from which may be derived probabilities of different weather outcomes over this century. Academic outputs will include an extensive assessment of the carbon reduction potential of active and passive systems and designs for new and refurbished buildings. They will utilise case studies with PC simulation of the building and systems, employing the new probabilistic weather data. These assessments will provide designers and policy makers with guidelines to help reduce the growth in greenhouse gases (GHGs) from buildings, which at present contribute about 50% of the UK emissions. Other academic outputs will provide the theoretical basis underlying the proposed consistent PC-based and manual design methodology with coincident, probabilistic future weather data parameters such as solar radiation, air temperature, wind speed and direction. It is known that solar radiation and air temperature have peak values at different times and on different days but current design methods do necessarily separate them so that over-design often occurs. A related academic output will be a theory underpinning the selection of the proposed new Design Reference Year (DRY) which will facilitate building design (including passive and active heating and cooling systems and comfort assessment) with simulation on a PC. The DRY will replace the currently unsatisfactory Design Summer Year. Solar radiation data, not covered in detail in the HadRM3 and UKCIP02 models, will be developed to satisfy designers' requirements. Likewise wind data (crucial to include since wind drives natural ventilation) although the confidence level will be lower. Rainfall duration and quantity are also important in the building design process because of drainage and rain penetration damage and designers' requirements will again be reviewed.'Urban heat island' effects (urban areas are often hotter than the nearby rural areas), briefly mentioned in the present Guide, will be incorporated in the new data, developing on SCORCHIO work to provide more realistic urban weather data. Local modification or downscaling will also be applied to generate data for other sites in the UK. This will enable the new Guide to cover more than the current 14 sites for which data were developed by Manchester for CIBSE.To ensure that the new, probabilistic outputs will be useful to professionals, and to reflect best practice in design, there will be strong stakeholder involvement through the formation of a Stakeholders Group, including Corresponding Members, which will include CIBSE, architects and software houses and housebuilders. Policy interests will be reached via the Department for Communities and Local Government, and DEFRA and their contractors, such as BRE. There will be links to the Manchester-led EPSRC SCORCHIO urban heat island and climate change project, UKCIP and the Tyndall Centre.