Summary of Changes to Approved Document Part L1A & L1B (Domestic)
The Government introduced new legislation on the 6th April 2006 concerned with the conservation of fuel and power to new dwellings and existing dwellings under refurbishment/alteration and extension additions. The Regulations under Approved Document L1A – Work in New Dwellings and Approved Document L1B – Work in Existing Dwellings provides guidance on how to achieve compliance and reduce C02 emissions as per the Government directive. The following list is a summary of the changes within these new documents. L1A – Work in New Dwellings 1. A target emission rate is required before work commences on site and will encompass all the information required to make a 20% saving in C0 2 emissions compared with the previous regulations. The type of information included would be the size and type of the property, orientation, insulation, heating, lighting etc. 2. To obtain this information you will be required to use a calculation method such as SAP 2005 for dwelling not greater than 450m2 and SBEM (Simplified Building Energy Model) for dwelling over 450m2. 3. This calculation must be carried out by a suitably qualified person. 4. Air pressure test will be required to all small developments with larger sites being required to do sample testing. L1B – Work on Existing Buildings 1. U-values for extensions and alterations are more stringent and will require greater thickness of insulation. 2. Any changes to heating, glazing, lighting has more emphasis within the approved document. There is a greater control on upgrading. 3. Where more than 25% of a building element is being upgraded, e.g. wall is being renovated, the whole of that element will need to comply with the new insulation / U-values indicated within Table 1 of the document L1B.
Enclosed are explanatory leaflets to help and guide you. If you have any further queries, please contact the Section on 01792 635636
Summary of changes to Part L1a 7 L1B April 2006 (jd4868)