Government poised to backtrack on Part L

A government consultation on changes to energy regulations is expected to water down carbon reduction targets compared with previously stated policy.

The previous government had said the 2013 version of Part L would cut carbon emissions by 25% compared with the 2010 version. But in the latest sign of the coalition rowing back on green measures, the consultation - due to be published on Thursday after Building went to press - is expected to contain carbon reduction targets of as low as 11% compared with the 2010 version.

A reduction of just 11% instead of 25% is the most likely outcome

Building understands that a reduction of 11%-20% is likely, with an 11% reduction viewed as the most probable outcome. This lower percentage reduction could be achieved with improvements to the building fabric and more efficient services. Achieving a 20% cut would require expensive renewable technologies and CHP systems which could threaten the viability of developments.

It is expected the government will continue with the so-called aggregate approach, which sets different carbon reduction targets according to building type.
The Part L consultation is also likely to include minimum standards for the energy performance of the fabric of housing as proposed by the Zero Carbon Hub. This varies according to housing type and could mean carbon reduction targets for apartment blocks don’t change but increase proportionately for detached homes.

The requirement to upgrade the energy performance of an existing home when building an extension is also likely to be included. The “consequential improvements” has been proposed before but never made it into Part L as forcing homeowners to upgrade when undertaking other improvements was seen as politically risky.

However, linking improvements to the forthcoming Green Deal, which removes the upfront cost to homeowners, could make it politically acceptable.