How much could you save by insulating your home?

1 Oct 2022
5 min read

Making sure your home is properly insulated is one of the easiest ways to reduce your energy consumption, and it could knock a big chunk off your energy bills, too. Here’s how much you could stand to save based on October 2022 energy bills.

In a world of smart technology and energy-saving apps, insulation isn’t the most glamorous method of energy conservation, but it is one of the most effective. Keeping heat outside during hot weather and trapping it indoors during cold spells means less reliance on your boiler or air-conditioner. That means less fuel usage and therefore a smaller carbon footprint on the planet, plus lower energy bills for you.

How much could you save?

Loft insulation: save up to £590 a year for a detached house

Man laying loft insulation

Decent loft insulation will last for around 40 years, and will pay for itself over and over again

As much as a quarter of heat is lost through the roof in an uninsulated home, so there are big savings to be had here. Decent loft insulation will last for around 40 years, and will pay for itself over and over again.

There are several ways to insulate a loft – most of the time you can even do it yourself. According to the Energy Saving Trust, insulating the loft of a detached house will cost around £630, but that will save £590 in energy bills every year, as well as stop 950kg of CO2 from entering the atmosphere – that’s the same amount emitted by a car driven for 2,323 miles.*

For a semi-detached house, loft insulation will cost around £480, with £355 savings every year, while insulating a mid-terrace house will cost around £455 and save £330 a year.

All the cost figures are based on using a qualified installer. However, if you were able to undertake the work yourself, seeking the appropriate advice beforehand, then the costs of loft insulation would be cheaper.

Cavity wall insulation: save up to £690 a year

Around a third of a home’s heat is lost through uninsulated walls

Newer houses built from the 1990s onwards already have pretty good wall insulation in place, but older homes can see significant improvements, especially if you’ve got cavity walls. These are walls made up of two separate walls with a gap in between, usually found in homes built after the 1920s. Around a third of a home’s heat is lost through uninsulated walls.

Cavity wall insulation isn’t something you can do yourself, so you’ll need to get a registered installer to do the job. But it’s a quick, mess-free process that should only take a couple of hours. According to the Energy Saving Trust, it’ll cost around £1800 to insulate the walls of a detached house, which in turn saves an average of £690 on your yearly energy costs as well as a whopping 1080kg of CO2 – which is the equivalent of charging 137,713 smartphones.*

For a semi-detached house costs range around £1,000 with £395 of savings per year, while a mid-terrace house would cost around £580 to insulate, saving £235 per year.

Floor insulation: save up to £180 a year

Floor insulation is a great way to keep your home warm and cosy, and the good news is you usually only need to insulate the ground floor of your property to feel the benefit. Newer homes have floors made of solid concrete, which can be fitted with rigid insulation. Older homes with timber floorboards can be insulated with layers of mineral wool insulation installed between joists.

The costs involved will vary depending on the type of flooring you have and the size of your floorspace, and whether you get professionals in to do the job or tackle it yourself. Typical installation costs vary between £1,600 and £2,900.

Figures from the Energy Saving Trust suggest insulating the floor of a detached house will shave around £180 a year off your energy bills and save about 290kg of CO2 – the same as recycling 12.7 rubbish bags of waste, instead of sending them to landfill*.

Semi-detached properties will save around £110, while mid-terraces will save around £75. This type of insulation has a longer payback time than others, but you’ll feel the toasty warm benefits straight away.

Other quick fixes: save up to £300 a year

There are plenty of quick and easy insulation jobs you can do yourself

There are plenty of quick and easy insulation jobs you can do yourself. The word ‘insulation’ often conjures up images of complicated building work, and while some types of insulation – loft and cavity wall, for example – can require getting professionals in, there are plenty of quick and easy insulation jobs you can do yourself that will make a big dent in your energy consumption and bills. Here are some changes you can make in a single afternoon.

  • Fit a hot water cylinder jacket. They cost around £15 and will cut your energy bills by around £80 a year – that’s a significant payoff.
  • Draught-proof windows and doors using foam strips, door brushes, letterbox flaps and keyhole covers. The cost will depend on the kit you buy, but will be relatively low and you can expect to save around £125 a year on bills. Take care not to obstruct any intentional ventilation, though.
  • Block up chimneys if you’re not using your fireplace. A chimney draught excluder can cost as little as £5 and could reduce energy costs by up to £35 a year.
  • Turn down heating by 1 degree: £145
  • Turn off radiators in unused rooms: £55 (based on using TRVs).
  • Reduce dishwasher load once a week, saving is £17

For more information on insulation, check out our guide to keeping your home warm and cosy in winter, or find out how to use insulation to reduce your gas bills even further.

* Figures from EPA’s Greenhouse Gas Equivalencies Calculator


The information in this article was correct at the time of writing and is provided for guidance only. Please see the full disclaimer in our terms and conditions.

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