Part L 2006 Legislation

The new Part L Regulations came into force on 6th April 2006.

For all new buildings compliance to Part L is now based entirely on the reduction of carbon emissions and by production of an Approved Energy Rating calculation.  All previously used methods of compliance are now obselete.

To comply to Part L1A (new dwellings) a calculation is done to show that the carbon emissions from the proposed dwelling (the DER) are no greater than a Target Rating (TER.) An additional calculation ensures that the final “as built” project compares favourably with the original specification.

In document Part L1B (work in existing dwellings) for small works compliance can still be gained by achieving set elemental U-values for the floors, walls and roofs. Alternatively, a carbon emission calculation can be done before the works and then after, with the carbon emissions being no worse than that of the existing dwelling.

Under the Approved Document Part L2A (Work in new Buildings other than dwellings), significant changes have taken place in compliance.

To show compliance CO2 emissions from the proposed building, the Building Emission Rate should be no greater than a pre determined target rating which is determined from a SAP type calculation called the Simplified Building Energy Model (SBEM).

Under Document Part L2B (work in existing buildings that are not dwellings) there is a need for ‘consequential improvement’. Where work involves an extension, the installation of fixed building services or an increase in capacity of these building services, there is a need to improve the energy performance of that building.