Welsh Government publishes circular on building regulation energy efficiency amendments
The Welsh Government has published Circular WGC 003/2026 to introduce the Building etc. (Amendment) (Wales) Regulations 2026, amending the Building Regulations 2010, SI 2010/2214 and related legislation in Wales. The Regulations introduce new energy efficiency requirements under Part L, effective from 4 March 2027, including a revised definition of fixed building services, the revocation of provisions on nearly zero energy buildings and high-efficiency systems, the replacement of the energy efficiency rating with an energy use intensity metric, and a new requirement for on-site renewable electricity generation in new dwellings and buildings containing dwellings. Approved Documents L1, L2 and F1 will also be updated. From 1 July 2026, further amendments implement aspects of the Building Safety Act 2022. These reforms change building control procedures, require completion notices for work reverted to local authorities, align dutyholder definitions, and require disclosure of unresolved contravention notices, with new grounds to reject Initial Notices. Plan checking for higher-risk buildings remains a restricted activity and transitional provisions allow projects that have already commenced or notified before specified dates to continue under the previous regime.