More than one home every minute will need to be refurbished in the UK between now and 2050, experts say.
The authors of a report to Parliament say 25 million existing homes will not meet the insulation standards required by mid-century.
The UK needs to cut carbon emissions by 80% by then – and a third of those emissions come from heating draughty buildings.
The government said it would devise policies as soon as possible.
But critics say ministers have been far too slow to impose a national programme of home renovation which would save on bills and improve people’s health, comfort and happiness. It would also create thousands of jobs.
Successive governments have been criticised for failing to tackle the UK’s poor housing stock – some of the worst in Europe.
Local authorities have limited cash to insulate council homes, and landlords and owner-occupiers have proved reluctant to invest large sums in disruptive improvements that will save on bills, but take many years to pay off.
The report from a group of leading construction firms – the Green Building Council – says four out of five homes that will be occupied in 2050 have already been built.
That means 25 million homes need refurbishing to the highest standards by 2050 – at a rate of 1.4 homes every minute.
Who pays?
The authors say this huge challenge also offers an unmissable opportunity under the government’s infrastructure agenda. The fiddly business of insulating roofs, walls and floors creates more jobs and has more benefits than any existing infrastructure priority, they maintain.
The question is how to pay. The government’s Green Deal scheme for owner-occupiers collapsed amid a welter of criticism that interest rates for insulation were too high, and that the insulation itself was too much hassle.
It says the construction industry needs certainty about what it is expected to deliver, and measurement to discover what is already being built. This should stimulate innovation, it says.
Julie Hirigoyen, head of the GBC, told BBC News there was a great prize to be grasped in upgrading building stock: “People will have warmer homes and lower bills; they will live longer, happier lives; we will be able to address climate change and carbon emissions.
“We will also be creating many thousands of jobs and exporting our best skills in innovation.
“Driving up demand for retro-fitting homes is essential for any policy to be a success – the Green Deal told us just offering financial incentives isn’t necessarily the only solution. We need to make it all easy, attractive and affordable.
“The good thing is that the business community is really starting to recognise the opportunity.”