Question to the Ministry of Housing, Communities and Local Government:

To ask the Secretary of State for Housing, Communities and Local Government, pursuant to the Answer of 30 June 2025 to Question 62017 on Housing, whether his Department has made an estimate of the potential impact of Part O on internal temperatures.

Part O of the Building Regulations, which aims to address the risk of overheating in new residential buildings, came into force in June 2022. A transition period was put in place to minimise disruption to projects that were already underway and to allow industry time to adapt to the new Part O requirement. As a result, not all developments were immediately subject to the Part O requirement and the Department’s understanding of the impact of Part O is still developing.

However, as part of the Future Homes and Buildings Standards consultation, we sought evidence on whether Part O is appropriate or whether it requires amendment. As mentioned in response to Question 62017, the Government will set out the evidence it received on Part O during this consultation and its response to this later this year, when the Future Homes and Buildings Standards consultation response will be published.