The British government has published plans for making cuts in greenhouse gas emissions in every sector of the economy.
The government says it wants to meet its targets in global warming reduction.
Each sector is being set a 2020 carbon budget with housing required to cut energy use by almost 30%.
Energy Secretary Ed Miliband said Britain will produce 40% of its electricity from low-carbon sources by 2020.
Environmentalists welcomed the plan but said urgent action rather than words was needed.