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 4 September to Question 73498 on Housing: heating, what recent estimate his Department has made of the average efficiency rating of radiator systems being installed in new-build properties.

The energy performance of radiator systems in new-build homes is governed by the Building Regulations, which are the responsibility of the Ministry of Housing, Communities & Local Government. Associated statutory guidance is provided in the Approved Documents which accompany the Building Regulations. We draw on evidence from industry and the public to inform Approved Document guidance and ensure new homes are high-quality and energy efficient. While the Future Homes and Buildings Standards consultation did not include specific questions on sizing radiators, the existing Approved Document L Volume 1 provides guidance on this.

This guidance was last updated in 2021 following two consultations which provided housebuilders and end-users with the opportunity to provide feedback, and an impact assessment was published at the time of implementation. Separately, the Department for Energy Security and Net Zero recently ran a consultation on raising product standards for space heating. This set out proposals which would drive improvements in the efficiency of new heating appliances and closed in March 2025.