Building Regulations and Energy Efficiency
This page gives guidance on complying with the sections within Part L of Building Regulations that cover the energy performance of existing buildings.
The Building Regulations set standards for how buildings must be constructed or altered to achieve a minimum level of acceptable performance. The regulations apply mainly to new buildings and there is no general requirement for all existing buildings to be upgraded to meet these standards. However, certain alterations such as the change of use of the building or renewing some of its elements can trigger the need to comply.
Although the Building Regulations only state general requirements, they are supported by Approved Documents which set practical guidance to help with meeting these requirements.
Approved Documents Part L1B and L2B cover work to existing dwellings and existing buildings that are not dwellings.
These documents can be accessed from the planning portal.