Approved Document L

About Approved Document L

Approved Document L gives guidance on the conservation of fuel and power, with separate guidance for dwellings and for buildings other than dwellings. It covers the energy performance of new buildings, work on existing buildings, and the heating, hot water and other fixed services in them.

What it covers

• Energy performance calculations for new buildings
• Performance of the building fabric and continuity of insulation
• Airtightness and pressure testing
• Heating, hot water, lighting and other fixed building services
• Work on existing buildings and consequential improvements
• Commissioning and giving information to the building owner

• Read our guide to Part L and the Future Homes Standard