-:- Approved Document L1B -:-
Conservation of Fuel and Power in
Existing Dwellings
Part L1B is the guidance document that should be used for any work to an existing dwelling or to an existing building that is being converted into a dwelling. Domestic extensions, barn conversions and internal domestic alterations should all be assessed using L1B. These Regulations require all new dwelling that are formed from existing buildings, such as the conversion of a mill building into apartments or splitting an existing house into two or more apartments to be assessed and a SAP Rating provided. There is not a requirement to show compliance through achieving a Target Carbon Dioxide Emission Rate (TER). For domestic extensions are limited in the amount of glazing permitted within the Building Regulations. However it is normally possible to show that glazed extension comply with the Building Regulations by completing a SAP assessment on the existing house that has had some energy efficiency improvements carried out and the extension.
Renovation and repair of thermal elements is now included within the building regulations and when carrying out renovation work to poorly insulted thermal elements then insulation should be introduced. This work would include re-roofing a slate roof, re-felting a flat roof, replacing a timber floor with a concrete floor and rendering a wall. The improvement work to existing dwellings should be economically feasible and this is shown by the improvement work having a 15 year payback period. Any work that can be shown to achieve a payback of greater than 15 years would not have to be completed.
Gladwood (BCS) Ltd can complete the SAP 2005 assessment and produce SAP Certificates for building work that creates new dwellings, and show that extensions with large areas of glazing still meet the Regulations. We can produce improvement schedules and simple payback calculations when renovation or repair work is being carried out on existing thermal elements.
