The 10% increase in the energy price cap will cause unrest across the UK, but one group will be hit particularly hard by the high prices: people living in uninsulated, poorly built homes and potentially at the lower end of the income scale.

This group now has to pay even more to keep their homes warm and leave the heating on longer.

Energy experts are calling on the government to come up with a serious plan to insulate Britain’s leaky homes.

The new price cap will see the average annual energy bill for gas and electricity rise to £1,717. This is an increase of £149 from the current price level of £1,568, which has been in place since July.

The majority of UK homes – around 80% – are heated by natural gas. The country’s housing stock is also in a poor state: here in the UK we have the worst insulated homes in Western Europe. This means that when gas prices rise, the price of heating Brits goes up. So we buy expensive gas to heat our homes and then much of that heat is lost through our walls and roofs.

Jess Ralston, head of energy at the Energy and Climate Intelligence Unit (ECIU), said: “Due to a lack of progress on energy efficiency and heat pumps, our reliance on gas has not fallen significantly in recent years, despite volatility in international markets driving up bills. The new government has taken steps towards renewable energy but has not yet confirmed its plans for heating or insulating homes, and there is clearly no time to lose.”

Much of the blame lies with former Prime Minister David Cameron. His decision to scrap compulsory home renovation schemes means the country is lagging far behind in improving the heating performance of homes. Annual energy efficiency installations peaked at 2.3 million in 2012, thanks to government subsidies. This has now fallen sharply to around 100,000 upgrades per year.

Rishi Sunak last year abandoned plans to force landlords to upgrade their homes to a C-grade or higher energy performance certificate and disbanded a working group on energy efficiency. Labour could make a difference for private renters living in draughty homes by reintroducing these certificates.

Emma Pinchbeck, CEO of industry group Energy UK, said: “It would be good if the Government had plans for heat,” adding: “Our best tool to protect the economy and all our customers from these high prices is to reduce demand for imported gas. Here the new Government is right to focus on expanding renewables and investing in insulation.”

A spokesman for Ed Miliband, the Secretary of State for Energy, Security and Net Zero, said: “Doubling the warm homes plan from £6.6 billion during the general election to £13.2 billion is the biggest single investment we will make and the biggest in British history.” It will insulate 5 million extra homes. That’s a start, but politicians and energy experts argue it’s not enough.

The government has also not yet unveiled plans for new housing: will builders be forced to build homes with heat pumps or solar panels on the roof, or will there be stricter insulation regulations? Labour will face intense lobbying from the construction industry, which will argue that stricter regulations will make it harder and more expensive to meet construction targets.

And finally, we are still in the dark about how the Government thinks homes should be heated, although Miliband said before the election that the Conservative Government’s ban on installing new gas boilers would be lifted by 2035. This means the party will have to find alternative ways to encourage the use of non-fossil fuels for home heating.

This is crucial if the country is to reach net zero; heating the UK’s 28 million homes accounted for 18% of all UK greenhouse gas emissions in 2021.

The government is under pressure from the Greens on all these issues. Co-leader Carla Denyer said: “The government has said that the creation of GB Energy will reduce bills in the future, which would be welcome. But this goal will only be achieved if the government also invests in improving the energy efficiency of homes.”

“We need an immediate, nationwide, government-funded and local authority-run home insulation program to help people keep their bills permanently low.

“We could reduce bills in the long term and help reduce greenhouse gas emissions by building new homes that are easier and cheaper to heat, and improving the insulation of existing homes. Insulating people’s homes means they stay warm while using less energy, saving money and producing fewer harmful carbon emissions.”

Doug Parr, policy director at Greenpeace UK, added: “Unless the Government introduces a national home insulation programme, promotes renewable energy and introduces a social tariff on energy bills, this crisis will continue winter after winter. This should be a wake-up call for the new Government to deliver on its promises and reduce bills.”