The Planning and Regeneration Committee met on Tuesday 10 March 2026 to discuss the significant risks posed by extreme heat to London's housing stock and the wider implications of climate change. The committee heard from a range of experts and stakeholders about the current challenges and potential solutions, with a particular focus on the need for improved data, strategic adaptation, and the role of both passive and active cooling measures in new and existing homes.

Overheating Risks in London's Homes

The meeting highlighted the growing threat of extreme heat to London's housing stock, exacerbated by the urban heat island effect. Temperatures in built-up areas can be up to 10°C higher than surrounding areas, and the summer of 2022 saw record temperatures of 40°C, leading to over 3,000 excess deaths in England, with 387 in London. These risks disproportionately affect vulnerable populations, including the elderly and those with pre-existing health conditions.

Experts noted that overheating is already a significant problem, with estimates suggesting that nearly 75% of social housing in London is at high risk of overheating. This issue is projected to worsen with climate change, potentially leading to more frequent and intense heatwaves. The increasing adoption of air conditioning, while offering a solution, also poses risks to the energy grid and could lead to cooling poverty if not managed sustainably.

Adaptation and Mitigation Strategies

A key theme throughout the discussion was the need for a systematic and multi-faceted approach to adaptation and resilience. This includes:

• Green Infrastructure: The importance of green spaces, trees, and other natural solutions was repeatedly emphasized for their role in dissipating heat. Even a single tree can reduce temperatures by up to 8°C. However, the challenge of integrating green infrastructure into densely built-up areas and the potential conflict with Green Belt land were also acknowledged.
• Building Design and Regulations: The committee explored the effectiveness of current building regulations, such as Part O of the Building Regulations, which aims to address overheating in new builds. However, concerns were raised about the lack of data to prove their effectiveness and the challenges in enforcement. There was a call for a review of regulations to ensure they are fit for purpose for future climate projections, including the potential removal of requirements like dual-aspect flats if they hinder climate resilience.
• Active Cooling: While passive measures are preferred, the necessity of active cooling, such as air conditioning, was acknowledged, particularly for extreme heat events. However, the focus must be on energy-efficient systems and avoiding lock-in solutions that exacerbate carbon emissions. The potential for hybrid heat pumps and waste heat recovery from cooling systems was also discussed.
• Data and Monitoring: A significant data gap was identified, particularly regarding real-time temperature monitoring in indoor and outdoor spaces, and the effectiveness of current regulations. There was a call for better data collection, including post-occupancy evaluations and an overheating index for homes, to inform policy and consumer choice.
• Risk Communication and Behaviour Change: The low perception of heat risk in the UK was highlighted as a barrier to action. Experts stressed the need for more persuasive risk communication, potentially through naming heatwaves and community-based interventions, to educate Londoners on how to protect themselves.

Policy and Investment

The discussion underscored the need for a coordinated policy response and significant investment. Key policy areas identified include:

• The London Plan: The cooling hierarchy within the London Plan was seen as a good starting point, but there was a call for better integration of policies related to energy, health, and the built environment. The potential for the London Plan to set tighter overheating regulations than national building regulations was also discussed.
• National Planning Policy Framework (NPPF): Recommendations were made to strengthen the NPPF to include a more strategic approach to preventing overheating and other climate risks, and to allow local authorities to set tighter overheating regulations.
• Retrofit: The lack of focus and investment in retrofitting existing homes was highlighted as a major concern, particularly for social housing and low-income households.
• Data Centres: The significant energy impacts of data centres were discussed, with a recommendation for a specific policy in the London Plan to manage their development and ensure they contribute to heat networks.
• Funding: The need for government funding for retrofit programmes and the potential for innovative financing mechanisms, such as land value capture, were emphasized.

The committee concluded that while London has made progress in addressing heat risks, there is an urgent need for more systematic adaptation, greater investment, and a cultural shift in how heat is perceived and managed within the built environment. The upcoming London Heat Plan is seen as a crucial step in this direction.