Climate change is the biggest threat facing our planet and will have a significant impact on building design and energy use. Our research is responding to this impact by creating weather files for the UK that can predict weather in 2080. These files provide, for the first time anywhere in the world, highly localised weather data mapped over a seven-day period at a spatial resolution of 5km.

Having this critical information will enable designers to assess energy performance and the risk of overheating in buildings under climate change. And this will lead to buildings better designed and constructed to deal with the more frequent extreme weather we expect to encounter in the future.

The hidden problem of overheating

For human survival, one of the most worrying aspects of climate change is the expected progression in extreme temperatures. Heatwaves are predicted to become more common as our atmosphere warms. Ensuring that buildings and systems have been tested with future weather predictions is an important strategy in reducing morbidity.

Overheating is a problem in the UK because, unlike in other countries, its homes and buildings are not designed to keep people cool. Around 20% of homes in England already overheat in normal summer conditions, and 80% of the UK’s housing stock will still be in use in 2050 when we can expect more extreme weather.

The greatest impact of exposure to high indoor temperatures will be felt in those over 65 years, or with disabilities or pre-existing medical conditions. In the last twenty years there has been a 53.7% increase in heat-related mortality in people over 65 years, reaching 296,000 deaths in 2018 worldwide.¹

Creating localised future weather for the built environment

The construction industry and building scientists use weather files for thermal modelling of buildings. But, the files currently used only represent average weather and cannot indicate extremes like heatwaves or cold snaps. Until now, these files divided the UK into only 14 regions making accuracy difficult. For example, the whole of the Southwest Peninsular (including up-land areas) is assigned the coastal Plymouth weather file. This leads to a 200% error in estimating annual energy demand.

At Bath, Professor David Coley and Dr Sukumar Natarajan are addressing this through an EPSRC funded project: 'The creation of localised current and future weather for the built environment' (COLBE). They have created a time series of weather in 2080 for 11,000 postcode locations in the UK for public download. By simply entering a post code, individuals can download a variety of computer files, each of which contain a year of possible local weather, now or in the future. This will greatly help individuals in visualising the impact that climate change could have in their own homes, within their own lifetimes.

Research into action: putting COLBE to work

The impact of the COLBE project is already making itself clear. The research is being taken out of the University for use in the real world with Bath & Northeast Somerset Council (BANES). In recent planning guidance, the council have stated that the weather files will be used to design buildings for future performance.

The mathematical framework that predicts future weather on a localised scale is now also being applied to a new project focusing on the Global South. The Zero peak energy building design for India (ZED-i) project aims to end peak energy demand in buildings in India. It will do this through a new science of zero peak energy building design for warm climates. This will provide scientists, engineers, and the public with weather files for both average and extreme weather at the unprecedented resolution of 25km across India.