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Insulation helps to keep your home warmer in the winter and cooler in the summer.

It works in the same way that a thermal flask does to keep tea warmer for longer, or a cold drink nice and cool.

The two most common types of insulation for the home are cavity wall insulation and loft insulation.

If you want to know what sort of insulation your home already has, you can check some things yourself.

For example, patterns of holes in your brickwork can tell you if you have cavity wall insulation. Cavity wall insulation is installed by drilling small holes into the external walls of a property.

You can also check the depth of loft insulation, if it is present, using a ruler. The recommended minimum depth of insulation is 270mm.

Topping up older insulation from 120mm to 270mm could save around £25 every year. If your home has no loft insulation, installing the recommend amount could save £250 a year.*

Illustration shows lightning bolt and wording which reads make a plan, stay warm, save energy.
Save energy with cavity wall and loft insulation

Our Green Doctors have identified helpful impartial advice on what can really make a difference in reducing bills and saving energy.

Download our supporting home resources – our action plan, our meal and shopping planners, and our stickers – to help you make changes which stick.

Cavity wall insulation

Most UK homes built between 1920 and 1990 will have a gap in between the internal and external walls. Cavity wall insulation fills this gap with insulating material.

illustration shows internal and external walls with insulation in between.
Save energy with cavity wall and loft insulation

Loft insulation

Loft insulation helps reduce heat loss through the roof (up to a quarter of a home’s heat escapes through the roof). Laying mineral wool under the rafters can help keep a home warmer in the cold months.

illustration shows sheets of insulation on the inside of a roof.
Save energy with cavity wall and loft insulation

What to know about getting insulation

Getting your home insulated for the first time can feel like a big deal.

There are websites where you can find out about trusted traders to carry out the work. You might also want to ask them some of these questions to help understand the work they recommend doing:

  • What type of insulation do you recommend for my home?
  • In what areas of my home would installing insulation provide the most benefits?
  • How much insulation is needed? How much will it cost?
  • How long will it take to install the insulation?
  • What kind of guarantees do you offer on your insulation services?

This can help you understand more about the likely cost savings you will get in the long-term.

For some households, adding insulation can feel like too much of an outlay at once. Fear not, there are schemes run by local authorities and energy providers that offer free cavity wall insulation.

If you home isn’t suitable for cavity wall insultation, there may be other options. Internal wall insulation (IWI) and external wall insultation (EWI) can offer real benefits for long-term energy savings.

You might also want to look at draught-proofing or thermal curtains to help keep your home warm.

Make a plan. Stay warm. Save energy.

  • Place one of our stickers on the washing machine as a reminder of your best settings.
  • If your washing machine doesn’t have an economy setting, look for the shortest, coolest cycle available.

*Savings based on a typical three-bedroom semi-detached gas heated house, with an 88% efficient gas boiler and average gas tariff of 6.9p/kWh and electricity tariff of 27.4p/kWh. Emission savings include all scopes and greenhouse gases expressed as carbon dioxide equivalent. Correct as of October 2023.

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Save energy with cavity wall and loft insulation