24 February 2011, 13:19 BST
Final recommendations on how the building industry can comply with the 2016 zero carbon homes target have been delivered to the government.
The Zero Carbon Hub presented the report on carbon compliance - the on-site reductions in carbon emissions - to housing minister Grant Shapps, including separate limits for different types of dwelling.
Originally the task group had suggested tightening the carbon compliance standard by 70 percent, however it now says this "may not be achievable in all cases".
The percentage savings set from 2006 standards are now 60 percent for detached dwellings, 56 percent for other houses and 44 percent for low-rise apartment blocks.
According to the task group, as the proposals are based on built performance, rather than designed performance, they are not comparable with previous recommendations.
David Adams, director of the Zero Carbon Hub and Task Group Chair, described the publication of the recommendations as "an important step toward finalising a workable definition for zero carbon homes".
"An early statement by ministers in response to these recommendations will further build confidence that the zero carbon objective is achievable and on track to be delivered," he added.
Last year, the government announced a similar target for new build commercial properties, which it intends to be zero carbon from 2019.
Source: Low Carbon Economy