Complaints about standard of cavity wall insulation installation


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This information is for domestic consumers who’ve had cavity wall insulation measures delivered through the Energy Company Obligation (ECO) scheme.

We have no role in the administration of other schemes such as those run by local authorities, and the Scottish, Welsh and Northern Irish governments. You can use this tool to find your local council.

Our role and ability to help

Our role as administrator of the ECO scheme generally involves setting targets for each obligated energy company, ensuring compliance and monitoring their progress towards these targets. We do not regulate the insulation industry.

Because we have no oversight of the contractual arrangements between the obligated energy companies and those organisations that install energy efficiency measures on their behalf, our ability to help you resolve a complaint is largely based on providing general advice, and in some cases providing information on the installation itself. 

That said, we are always keen to hear about any problems experienced with ECO measures by consumers so we can work with industry to improve standards.

The steps outlined below should help you resolve complaints about an energy efficiency measure installed in your home.

Step 1: Find your paperwork and contact the installer

Contact the installer responsible for your work. This should be in the paperwork given to you when the measure was installed. 

If you can’t find this information and the measure was installed in your property from April 2015 onwards, we should be able to confirm the name of the installer if we have the details registered on our database. To request this, please contact the ECO team and outline what information you wish to request, along with the full address the measure was installed at. (Please note that we will not have this information on our database until three months after the installation has been completed.)

You may also find the Citizen Advice’s ‘Letter to complain to a trader about poor quality work’ generator a useful tool to help you draft a letter to an installer if they’ve carried out poor quality work.

If your measure was installed before April 2015, the energy company that helped to fund it may have a record of the installer’s name (see step 5) and may be able to help you.

Step 2: Contacting an oversight body

If the installer hasn’t or wasn’t able to resolve the issue then you should contact the relevant oversight body, as they may also be a part of an accreditation and/or certification body, and/or trade association that maintains industry standards.

If the cavity wall insulation measure was handed over to the consumer after 1 January 2020 and the measure was TrustMark registered, then TrustMark may be able to help you if things go wrong. This webpage contains useful information on how to help you reach a suitable conclusion.  

You can also search on the Green Deal Oversight & Registration body website where you may be able to find details of your installers’ certification body. Please note installers have to be registered by a certification body to be eligible under the Energy Company Obligation scheme. 

Step 3: If the installer has gone out of business

Citizen’s Advice provides general guidance on what to do if a company has gone out of business. If you live in Scotland, Home Energy Scotland may be able to provide you with suitable advice on how to resolve your concerns.

Step 4: Find your guarantee or warranty

If the measure was solid, cavity or mobile home wall insulation and installed under ECO, it should be covered by a guarantee and you should contact the guarantee provider. There’s a list of appropriate guarantee providers and their contact details on our website for ECO1 (January 2013 to March 2015) and ECO2 (including ECO2t) (April 2015 to September 2018). The current list of ECO3 appropriate guarantees can be found on the TrustMark website. Ofgem no longer administers appropriate guarantees or financial protection.

If you do not have your guarantee and the measure was installed before April 2015, you can contact all the guarantee agencies covering cavity wall insulation and ask them if they have a record of a guarantee covering your address.

For ECO measures installed after April 2015, we can confirm the name of the relevant guarantee agency for wall insulation, but we don’t hold this information for measures installed before then. Please contact the ECO team for more information.

Step 5: Contact the energy supplier

The contract for the work done in your home is typically between you and the installer. However, in some cases the energy company which ultimately funded the measure may be able to help and/or give you information on the installer or the guarantee provider. You can try contacting the supplier that funded your installation and explain the issues you are experiencing with your measure. If there is still an issue with your installation after following the previous four steps, it is found to be an ECO measure within the current scheme and the supplier wants to continue to count it towards their ECO targets, we would expect them to have a process in place that would assist with the rectification of the issues. We cannot guarantee, however, that the energy supplier will undertake remedial works.

Other help

If your problem is still not resolved, the Citizens Advice consumer helpline may be able to help. The number is 0808 223 1133 (or 0808 223 1144 for the Welsh speaking service) or they can be contacted online. If you wish to report a problem to Trading Standards, mention this to the adviser.

Citizens Advice can refer matters to Trading Standards, who will then decide whether to take on the case.

If you live in England or Wales and would like advice on energy efficiency, including energy saving schemes such as ECO, which you may be able to benefit from, the Simple Energy Advice website offers impartial energy efficiency advice and support. If you live in Scotland, you should contact Home Energy Scotland on 0808 808 2282 or complete their contact form.