Government plans to make homes more energy efficient may fail unless builders are forced to comply with new regulations, MPs have warned.
More than 80% of the expected efficiency savings by 2020 would have to come from changes to building regulations, the committee said.
The Commons public accounts committee also said households faced a "confusingly wide range of advice".
Houses were still using 8% more energy than in 1990 and usage would rise as more homes were built and people used more electrical appliances, the MPs said.
Energy consumption by UK homes had fallen encouragingly but efficiency levels lagged behind some EU countries. The government says household energy use must fall by 11% by 2010 and a further 2% by 2016, compared with 2001-05 levels.
The committee called on DCLG to check that all building control officers are fully trained and are using their powers effectively to enforce the energy savings requirements in the building regulations.
It added: "Little is known about the extent of compliance with the energy-saving parts of current building regulations, so the adequacy and effectiveness of the regulations on energy performance in practice is uncertain.
The Department for Communities and Local Government should set out a clear plan for testing energy performance routinely on a sample basis to check on compliance, the effectiveness of the buildings control regime and, ultimately, the effectiveness of building regulations in delivering reduced energy consumption.
Personally I think that the plans to make homes more energy efficient are a very good initiative of the government, because energy efficient buildings could reduce the needs of energy in the world, and these buildings can also help to control the global emissions of greenhouse gases, which is positive for the environment. Also the energy bills will be reduced because people are going to use less energy in the future because of these energy efficient buildings.
Dominique Van Huffel