That would mean thousands of owners having to pay for upgrades to their homes to attract a buyer.
The sudden cold spell has emphasised the poor quality of insulation in UK housing compared to other countries. Higher standards have already been imposed on new properties and are set to be made more stringent when new building regulations are introduced in a couple of years. These will also impose mandatory energy ratings.
But new property makes up only a tiny proportion of the country's 20 million homes, according to builders who have called for tougher controls on older properties.
John Gummer, the Environment Secretary, seems to have taken this message to heart. He told the National House Builders Council last week that homes have more impact on the environment than sources more usually condemned, such as cars. Each produces seven tonnes of carbon dioxide - equivalent to the weight of an elephant - each year.
'Building societies will come under increasing government pressure to insist on better energy ratings,' he said.
But Adrian Coles, director-general of the Council of Mortgage Lenders, rejected the suggestion that societies should become energy police. 'It is up to the individual how much they spend on energy,' he said. 'We would not impose rules on this any more than on how much food they bought.'
The average older home struggles to a score of four out of ten on a scale produced by the National Energy Foundation. Bringing these up to average, let alone the seven scored by new homes, would mean hefty bills.
Insulating a roof can cost up to pounds 250 and cavity-wall insulation pounds 350, according to a report by Which? last year. More substantial projects, such as double-glazing, can reach more than pounds 5,000, while super-efficient condensing boilers are more than pounds 1,000.
A typical house in Nottingham required work costing pounds 2,300, according to the NEF. But it said that for an average three-bed semi costing pounds 1,000 a year in fuel, simple draught-proofing and better insulation would at least compensate for extra VAT within a few years.Reuse content