Under new rules some non-domestic buildings will be allowed to achieve less than a 25% reduction while others will be expected to exceed the target

The communities department has today published the Approved Documents for Part L of the Building Regulations, which come into force in October.

The main changes outlined in the consultation for the 2010 version of the regulations, covering energy use, have been adopted including an across-the-board 25% cut in carbon emissions compared with current standards for all new developments.

The most radical change for non-domestic buildings is the adoption of an aggregate approach for the carbon emissions reduction, which will mean that some buildings will be allowed to achieve less than a 25% reduction while others will be expected to exceed the target.

Other key features put forward in the consultation for non-domestic buildings and adopted include the requirement for a design stage carbon dioxide emission rate calculation and supporting information to enable building control to understand the key features of the Part L compliance strategy as well as the need for an un-lodged energy performance certificate.

For domestic buildings a flat 25% reduction has been adopoted as recommended in the consultation. Again, a design stage calculation, including a list of specifications including key features is required. A commissioning plan is also required, setting out what systems are to be commissioned and what tests are required.

For existing homes, conservatories under 30m2 are still exempt from Part L, providing any walls, doors and windows separating the conservatory from the existing building are either retained or replaced, and providing the existing building's heating system isn't extended into the conservatory.

Approved documents for Part F, covering ventilation, and Part J on heating appliances, have also been published along with three new compliance guides.

10 point guide to Part L