Building Regulations Part L is the primary mechanism by which new developments are being forced towards zero carbon emmission. Compliance with Part L is based on calculations using either SAP (domestic) or SBEM (commercial). Each element of a building must comply with the individual requirements of Part L and additionally the calculated Emmissions Rate must be less than a Target Emmissions Rate (TER). The TER is calculated by determining the energy rating for a building of the same layout as the designed building, with all elements meeting the individual requirements, but with a significant (e.g. 25%) overall improvement.

Part L 2010 will increase the requirement further and it is intended that by 2016 the TER will be zero - i.e. zero net carbon emmission.

The respective Heating, Cooling and Ventilation Compliance Guides are also very useful references.

Domestic

Part 1A - New Dwellings

Part 1B - Existing Dwellings

Also see:
Domestic Heating Compliance Guide

Commercial

Part 2A - New Non-Dwellings

Part 2B - Existing Non-Dwellings

Also see:
Non-Domestic Heating, Cooling and ventilation Compliance Guide