Home insulation: How can it cut energy bills?

Households that insulate their homes could save an average of £555 on their annual heating bills, according to the Energy Savings Trust.

The Government caps the typical annual energy bill for a household at £2,500 for the next two years.

Insulation is the process of trapping heat in a building, usually by covering externally exposed areas such as roofs, floors and walls.

Without them, indoor temperatures are difficult to maintain and homes can lose up to 45% of their heat, according to the Energy Savings Trust.

If the temperature drops very quickly after the heating is turned off, the house is probably not properly insulated.

The Energy Performance Certificate (EPC) that comes with UK properties shows how efficient they are, rated from A (the best) to G.

Depending on the property, the main types are:

Most heat is lost through the roof, so it should be a priority. About two thirds of UK homes have attic insulation.

Many properties have a cavity wall structure—a gap between interior and exterior walls—that also allows insulation to be inserted.

However, solid-walled buildings, which account for around 31% of UK households, need to be insulated from the outside.

Figures from 2020 showed less than 10% were affected.

The cost depends on the type, size and age of the property.

In a typical three bedroom semi-detached house in the UK, the Energy Savings Trust estimates that the installation of draft control measures plus cavity wall and attic insulation could save £555 on an average annual energy bill.

However, installing floor or solid wall insulation is more expensive and, in some cases, can take decades to pay for itself.

The Government recently announced £1.5billion to improve the insulation of low-income households in England.

It will be made available to local authorities and social housing providers to upgrade 130,000 homes.

The money comes from a £6.6 billion pot announced in 2021 as part of the government’s Heat and Building Strategy.

Other UK support for low-income households is available:

Home Energy Scotland and NI Energy Advice provide more information.

There is less help for higher earners.

The Green Homes Grant has been canceled and the government has not announced a replacement.

Activists hoped the UK government’s new energy strategy would include specific measures to encourage more and better insulation, but this has not been the case.

Former Ofgem boss Dermot Nolan said it was “a missed opportunity”.

Green Party co-leader Adrian Ramsay also criticized the approach: “A mass isolation program would drastically reduce bills – and ensure people have warm, comfortable homes – while tackling the climate crisis.”

The UK has some of the least energy efficient homes in Europe – largely because much of the housing stock is so old.

In 2020, the UK had 29.3 million domestic properties, 36% of which were built before World War II.

At that time, more than 12 million households had an EPC rating of D or worse.

The government has previously set a target of upgrading as many homes to Class C “where it is practical, cost-effective and affordable to do so” by 2035. By 2030, all “fuel-poor” households and as many rental apartments as possible should reach the same standard.

But critics say progress toward that goal has “fell off a cliff.”

Many newer homes continue to be built without basic insulation. In 2022, the UK climate advisory group UKCCC warned the government: “We’re still building new houses that don’t meet minimum standards for efficiency.”

Around 35% of UK property is either council or privately let – and these are probably the least efficient, according to the Energy Savings Trust.

Although private tenants can only take limited steps to improve insulation, landlords in the UK can be fined up to £5,000 for renting properties with an energy performance rating below E and up to 2028 C.

Local authorities in England can apply for financial support from the Social Housing Decarbonisation Fund to improve the energy efficiency of their housing stock.