Homes in the north of England are more energy efficient than those in the South, a survey has revealed.
British Gas suggests turning the thermostat down one degree
Knowsley in Merseyside came out as the best region in the country for conserving energy. Camden in London was at the bottom of the list.
The British Gas survey of one million households was carried out to raise awareness of how much energy is wasted.
The company suggested making changes such as using energy saving lightbulbs and turning the thermostat down.
Other advice includes switching off unused lights and switching off cable or satellite boxes at the wall.
MOST EFFICIENT PLACES
Kingston upon Hull
The Energy Savers Report graded 65% of all households a D or worse for energy efficiency.
Amanda Mackenzie, brand director for British Gas, said: "One in every three pounds spent on energy in the UK is wasted through poor energy efficiency.
LEAST EFFICIENT PLACES
Kingston upon Thames
Kensington & Chelsea
Epsom and Ewell
Richmond upon Thames
"Energy waste is a global issue but if we all do our bit to reduce waste then we can permanently cut our energy bills and help to save the environment."
Environment Secretary David Miliband said: "Tackling climate change is one of the biggest challenges facing us today.
"We can all make a difference by thinking about the energy we use in our homes and identifying where our homes waste energy."