The Cost of Cavity Wall Insulation in the UK

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How much does cavity wall insulation cost in the UK?

The size of a property will determine the estimated cavity wall insulation price, but Checkatrade research has set out the ballpark cost averages in the UK as follows:

• The average price of cavity wall insulation for a flat is £950.

• The average price of cavity wall insulation for a mid-terrace property is £1,800.

• The average price of cavity wall insulation for a bungalow is £2,400.

• The average price of cavity wall insulation for a semi-detached property is £2,700.

• The average price of cavity wall insulation for a detached property is £4,600.

However, setting out a budget to cover the costs of cavity wall insulation needs to include these aspects as well:

• A cavity wall insulation survey can be as much as £300. A surveyor needs to be hired to carry out this inspection though, as they will be able to determine if it is a suitable option for a property and ensure walls being insulated are in a good condition.
   

• Cracks to the exterior of brick walls must be repaired before applying cavity wall insulation, to avoid the property becoming vulnerable to dampness. Repairs to a brick wall can cost between £240 and £300 each day.
   

• Loose wall ties have to be replaced ahead of cavity wall insulation being applied. This will be at a cost of around £30 to £50 per m², but the work needs to be done so that the wall ties can secure the pair of wall leaves at an even width.

Are cavity wall insulation grants available in the UK?

Property owners who express concern about affording the cost of cavity wall insulation should be directed to the GOV.UK website to see if they can get support through the Great British Insulation Scheme.

Cheaper or even free cavity wall insulation may be available if a property has an energy performance certificate of D to G. Those with properties in Council Tax bands A to D in England, and Council Tax bands A to E in Scotland and Wales could be eligible for support too.

Applications for cavity wall insulation grants through the Great British Insulation Scheme can be carried out by property owners, landlords or tenants, though the latter group will need permission from a landlord ahead of cavity wall insulation being installed.

Grants may also be available to property owners across Great Britain from energy suppliers, through the Energy Company Obligation (ECO) scheme.

A government initiative, the ECO scheme has been set up to support energy efficiency measures being put in place inside the properties of people who are considered to be in fuel poverty. Examples include upgrading heating systems or installing insulation.

This is achieved as the ECO scheme places a Home Heating Cost Reduction Obligation on medium and large energy suppliers. Click here to see the full list of suppliers involved and how to contact them about the help that they have available.

How much does cavity wall insulation removal cost?

As well as being installed, there are instances when cavity wall insulation will need to be removed from a property. 

These reasons include when the existing cavity wall insulation has:

• Become outdated.

• Become compressed.

• Started to degrade.

• Been damaged by mould.

• Been identified as causing internal damp issues.

• Been infested with vermin.

• Not been installed correctly.

• Been installed into a property that is not suitable for this type of insulation.

According to further research by Checkatrade, the average cavity wall insulation removal cost in the UK as of May 2024 is £21.50 per m².

Specialist tradespeople should be sought for such a job too, as they will have the skill to quickly remove the insulation without causing damage to walls or other parts of a property. 

Have you been asked to install cavity wall insulation into a property? Click here to purchase all the quality materials needed to complete the job to the highest standards.