A free door-to-door programme should be offered to households across the UK, giving advice on energy efficiency to tackle the country's power "crisis", according to a union.
Unison said consumers could save up to £600 a year through tackling poor insulation alone.
A national drive to make sure every house meets minimum energy-efficiency standards would be cost-effective, Unison argued.
General secretary Dave Prentis said: "The UK's energy supplies have reached crisis point and the Government must take action to bring millions of households in from the cold.
"Unless the Government invests in a long-term strategy to preserve our dwindling North Sea gas supplies, we will be relying on expensive imports and widescale fracking for shale gas."
Low-income households should be allowed £10,000-worth of free energy-efficiency work on their homes, while others should be offered a long-term interest-free loan, said Unison.