Energy efficient home improvements that actually pay back

Energy efficient home improvements are usually presented as a long list of equally good ideas. They are not equally good. Some are free, some pay back in a season, and some take fifteen years.

The principle worth holding onto is fabric first, then the heating system: stop the heat escaping before you spend money on making more of it. A heating system is sized to a house’s heat loss, so insulating after you install means you have paid for a system bigger than the house now needs.

Start with the free ones

Two changes cost nothing and are worth doing this week.

Turn the boiler’s central heating flow temperature down to 60C. On a condensing combi left at the factory setting of 80C, this is worth around 9 per cent of the total gas bill, because a condensing boiler only condenses, and only reaches its rated efficiency, when the water returning from the radiators is cool enough. Full detail in how to reduce your gas bill in winter.

Set the timer and thermostat to match how you actually live. Heating an empty house is paying for warmth that leaks away with nobody in it. Our guide to home heating controls covers the five layers of control and the order worth fitting them.

Neither costs a penny, and together they take about half an hour.

Then the fabric, cheapest first

Draught proofing. Doors, letterboxes, floorboards, loft hatch. Very cheap, largely DIY, and it stops a surprising amount of heat walking out of the building.

Loft insulation. Around a quarter of an uninsulated home’s heat is lost through the roof. Loft insulation lasts for decades with no maintenance and no moving parts, which makes it the most reliable measure on this page. If yours was done years ago, check the depth rather than assuming it is still adequate.

Cavity wall insulation, if the property has cavities and they are empty. Quick to install and effective. Not every house has them, and some cavities should be left alone, so it needs checking rather than assuming.

Solid wall insulation is genuinely effective and genuinely expensive, internally or externally. It is a decision, not a quick win, and usually only makes sense as part of wider renovation work.

Glazing. Double glazing keeps rooms warmer and less draughty, and it is one of the things buyers and surveyors look for. Payback on replacing sound double glazing with slightly better double glazing is long, so prioritise single glazed or failed units rather than upgrading what already works.

Our guide to the types of home insulation goes through which suits which property.

Then the heating system

A new boiler, if the old one deserves replacing. An A-rated condensing boiler wastes under 10 per cent of the gas it burns; a G-rated non-condensing one can waste over 30 per cent, which is £30 of every £100 you spend. Replacing a fifteen year old boiler is a real gain. Replacing a well maintained eight year old A-rated one is not, and we will say so. Boiler ratings explained covers the bands, and new boiler installation covers cost.

An annual service, which is the cheapest efficiency measure that involves an engineer. A dirty burner, a sludged filter and a flat expansion vessel all quietly cost you money before anything actually breaks. £80 fixed, about an hour, 20 checks.

A heat pump, if the fabric is up to it. Three to four units of heat per unit of electricity, and the only measure here with a £7,500 grant attached. It suits an insulated home with space for a hot water cylinder, and it is the wrong answer for a leaky one, which is the fabric-first point again. We compare it against the alternatives, including a modern gas boiler, in alternatives to gas central heating boilers.

Smart controls and radiator valves, so you stop heating rooms nobody is in.

What help is available in 2026

The Green Homes Grant closed in 2021 and has not returned. Two schemes are live now:

• The Boiler Upgrade Scheme. £7,500 towards an air or ground source heat pump in England and Wales, rising to £9,000 for homes heated by oil or LPG where the installation completes between 21 July 2026 and the end of March 2027. The EPC requirement was removed in April 2026. Your MCS certified installer claims it and discounts it from the invoice. Full rules in our Boiler Upgrade Scheme guide.
• ECO4. Funds insulation and some heating upgrades for households on qualifying benefits or low incomes. Extended to 31 December 2026, though most funding is already allocated. See heat pump and boiler grants for who qualifies and what we apply for on your behalf.

There is no grant for replacing a gas boiler with another gas boiler.

The mistake worth avoiding

Doing it in the wrong order.

The common version is fitting an expensive new heating system into an uninsulated house, then insulating a year later and discovering the system is oversized for the house it now serves. Oversized systems cycle, cycle badly, and cost more to run than a correctly sized one would have. The reverse mistake, insulating a house so well that a tired boiler short cycles, is rarer but real.

The way to avoid both is a heat loss assessment before you commit to a heating system, which tells you what the house actually needs rather than what a rule of thumb suggests.

If the work is part of a bigger renovation, timing matters as much as order. Our guide to what it costs to rewire a house sets out the order of trades and the heating jobs that are far cheaper while the floors are already up.

Find out what your house actually needs

We will look at the property, tell you honestly where your money is best spent, and quote the heating work fixed. If the answer is that you should insulate before you spend anything with us, we will tell you that, because a system sized for an improved house is cheaper than one sized for the house you have now.

Get a fixed-price quote, book an £80 boiler service, or call 0800 980 6018 and speak to someone in Bradford. We cover BD, LS, WF, HD, HX and HG.

Scheme figures checked 7 September 2026. Government schemes change, so we reconfirm live amounts before any quote.