For anyone planning an extension, a conversion or a refurbishment, the rules changed on 1 October 2010. From that date the Building Regulations 2010 replaced the Building Regulations 2000, and new editions of the approved documents took effect, including a tougher Part L on the conservation of fuel and power.
What changed
The 2010 regulations largely consolidated the earlier rules and their many amendments into one set. The bigger practical change was Part L. For new buildings, the carbon targets were tighter. For work to existing buildings, the guidance in Approved Documents L1B (dwellings) and L2B (other buildings) set higher standards for:
- new and replacement windows and doors;
- renovation of walls, floors and roofs, where a significant part is being renewed;
- replacement boilers and heating controls;
- extensions and conversions, including changes of use.
Transitional arrangements
Work was generally assessed under the old rules if plans or a building notice were deposited before 1 October 2010 and the work started within a year. Anyone with a project close to the line needed to check with their building control body before assuming which standard applied.
What it means for an owner
- Budget for it. Better insulation and glazing standards can add cost, especially when a roof or wall is being stripped back anyway.
- Design it early. Insulation adds thickness. In a loft conversion or a dry lined wall that can affect head height, window reveals and floor levels.
- Specify it properly. A specification that simply says “comply with Part L” leaves the contractor to decide. Clear details avoid disputes and variations later.
Older and listed buildings
Part L recognises that historic buildings need a different approach. Work that would harm the character of a listed building, or a building in a conservation area, or that would trap moisture in solid walls, may justify a lower standard. The aim is to improve energy performance as far as is reasonably practical without causing damage. This needs to be agreed with building control, and where listed building consent is needed, with the conservation officer too.
Getting the balance right is a design question, not a box to tick. Our Contract Administration service covers specification and building control liaison, and our Planning and Heritage service advises on older buildings. See how we took a Grade I listed town house from consent to completion.