Question 1

What is home retrofit and why does it matter?

Accepted Answer

Home retrofit means upgrading an existing home to improve its energy efficiency, for example adding insulation, replacing windows, or installing a heat pump. In the UK, homes account for around 14% of total carbon emissions. The government aims for all homes to reach EPC band C by 2035 for owner-occupied and by 2028 for rented properties. Retrofit can reduce energy bills by £500–£1,500+ per year depending on the measures taken.

Question 2

What government grants are available for home retrofit in the UK in 2026?

Accepted Answer

Several UK government grants support home retrofit in 2026: the Boiler Upgrade Scheme (BUS) offers up to £7,500 for heat pumps; ECO4 provides free or subsidised insulation and heating for eligible low-income households; the Great British Insulation Scheme (GBIS) covers loft and cavity wall insulation; and the Home Upgrade Grant funds energy improvements for off-gas-grid homes. Eligibility varies by income, property type, and location.

Question 3

How much does home retrofit cost in the UK?

Accepted Answer

Costs vary by measure: loft insulation £300–£1,500, cavity wall insulation £500–£1,500, external wall insulation £8,000–£22,000, double glazing £3,000–£7,000, air source heat pump £7,000–£13,000, and solar panels £4,000–£8,000. Havnwright's free retrofit calculator gives you a personalised estimate and shows which government grants you may qualify for.

Question 4

What is an EPC rating and why does it matter for my home?

Accepted Answer

An Energy Performance Certificate (EPC) rates your home's energy efficiency from A (most efficient) to G (least efficient). It is required when selling or renting a property in the UK. From 2028, rented homes must reach band C. A higher EPC rating means lower energy bills, a more comfortable home, and higher property value. Homes with EPC A–C sell for up to 14% more than those with lower ratings.

Question 5

Is home retrofit worth the investment?

Accepted Answer

For most UK homes, yes. Basic measures like loft insulation pay for themselves within 2–3 years through energy savings. More significant upgrades like heat pumps have a payback period of 7–12 years but can increase property value by £10,000–£20,000. With energy prices remaining high and government grants available to reduce upfront costs, retrofit is one of the best long-term investments homeowners can make.

Grant finder.

Check Your Eligibility

Available Government Schemes

Boiler Upgrade Scheme (BUS)

Energy Company Obligation (ECO4)

Great British Insulation Scheme

Social Housing Decarbonisation Fund

Local Authority Grant Schemes