As the UK concludes the summer of 2023 with yet another heatwave, it's a stark reminder of the earlier ones we experienced this year. Unfortunately, this summer set a new record for the highest global average temperature. The effects of climate change are becoming increasingly evident, and while home builders can play a role in mitigating these impacts, a significant difference lies in the comfort of our homes. The UK is amongst the top three countries expected to see the most significant rise in average temperatures.
Overheating homes
The realities of global warming are beginning to affect the comfort and safety of our daily lives. If the planet's temperature rises by 2°C, an alarming 90% of existing UK homes, as of 2022, will be vulnerable to overheating, with 55% of homes already experiencing overheated bedrooms during hot weather. The root of this issue lies in the historical design of UK homes, which were built to withstand cold winters rather than hot summers. However, new-build houses offer the advantage of efficiency and insulation, keeping homes warm and cosy during winter. Fortunately, insulation addresses both challenges; these materials are specifically designed to slow down heat transfer, retaining warmth in winter while repelling excessive heat in summer.
However, several other design elements significantly influence how homes absorb and retain heat. Windows play a critical role in this. Anyone who has spent time in a greenhouse or conservatory in July knows that more glass means more heat. Limiting windows on south-facing walls is a simple way to prevent excessive heat from entering. The 2021 update to Building Regulations introduced a maximum window surface area relative to floor space to counter these heat-trapping effects.
Looking to Mediterranean homes for inspiration, which are more accustomed to such issues, can also be beneficial. Increasing the use of shutters or external blinds that completely block light, as seen in the whitewashed homes of the region, effectively reflects rather than absorbs heat. Additionally, the UK’s climate offers the opportunity to harness wind for cooling through better ventilation. Windows that open, along with vents and fans, promote air circulation, which helps to reduce indoor temperatures.
While air conditioning might seem like an obvious solution to overheating, relying on it especially when powered by fossil fuels risks perpetuating a vicious cycle. Homes equipped with solar panels could use solar energy to maintain a cooler indoor environment. However, experts estimate that even with a 2°C increase in global temperatures, only 22% of UK homes would actually require air conditioning. Moreover, air conditioning contributes to the urban "heat island" effect, which is particularly pronounced in densely populated areas.
Cooling Systems
Surfaces like asphalt roads, pavements, and closely spaced buildings readily absorb heat, making urban areas like London up to 10°C warmer than their rural surroundings. The lesson here is to leverage the natural cooling effects of environmental features. Trees provide shade to sunny windows and can slightly cool the air, while grass keeps ground temperatures lower than paving or Astroturfing. Water features also help reduce ambient temperatures. Even buildings can benefit from natural materials; grass roofs and living walls act as insulation while also helping to lower ambient temperatures, similar to thatch roofs.
In our collective effort to combat climate change, it's crucial to consider measures that address the impacts we're already experiencing. While covering entire communities with grass roofs may not be the universal answer to overheating, thoughtful design and landscaping can significantly improve the comfort of occupants. As home designs evolve with changing lifestyles, addressing overheating must be a priority.
Source: LSL Land & New Homes
The Reeds Rains Content Marketing Team
