Cost is not the only factor in insulation.

Actually finding an installer in an industry literally decimated by government grant cuts is difficult.

Then, will you trust the installer in your home?

Then there are choices – insulating the outside of your walls is dearer than insulating the inside.

But insulating the inside shrinks your room size by a few inches.

Then comes what for many people is the biggest issue – the hassle.

In one experiment, a local council offered households a grant to insulate their homes. Many people said, “No – too much trouble.”

So the council offered to pay the whole bill. “No – too much trouble.”

Then the council offered to clear out the attic and fit insulation as a bonus. “Yes please”, came the response.

So, myriad problems – but if the government can’t solve this, ministers can kiss goodbye to carbon targets.

“It’s just not financially viable,” says John Donnellon, the CEO of Blackpool Coastal Housing, which manages the town’s council homes. “There needs to be grant aid to make it happen,” he adds.

And remember, the benefits of lower energy bills go to tenants like Jean, not their landlords.

The government acknowledged the importance of improving energy performance in buildings in its delayed Heat and Buildings Strategy published in October last year.

It talked about the need for a “fabric first” approach – improving the efficiency of walls and lofts before replacing heating systems. But the report came seven months after the government cancelled its £1.5bn “green homes grant” scheme.

That scheme – described as “botched” by MPs and closed after just six months – offered people up to £10,000 towards the cost of insulation. Just 47,500 homes were improved under the scheme, far fewer than the 600,000 that was promised at launch.

Chris Stark, of the Climate Change Committee, believes the government will need a new scheme because most homeowners cannot afford to insulate their homes.

As things stand, just a few tens of thousands of homes will install insulation this year, he says. “We really need to scale that up to something more like half a million a year and to do that quickly over the next four or five years.”

But with just £3.9bn earmarked by the government to supporting low-emissions homes, that may not happen as quickly as he hopes. The total is also well below the £9.2bn the Conservative Party said it would spend on energy efficiency by 2030 in its 2019 election manifesto.

Investing in insulation is “critical” if Britain is to cut energy consumption and meet its climate goals, says Jan Rosenow of the Regulatory Assistance Project, a clean energy think tank.

“About 23% of our emissions are from keeping warm heating our buildings. We need to bring those down,” he explains.

For years, low energy prices have made it more cost effective to just turn up the boiler. That’s why we’ve been caught out in the current energy crisis.

“Our homes, which we didn’t insulate because there was no need for it, are now much more expensive to run,” explains Mr Rosenow.