Get help with faulty solid wall insulation
This advice applies to Scotland. See advice for See advice for England, See advice for Northern Ireland, See advice for Wales
Date published: 4 June 2026
Your solid wall insulation might be faulty if you used one of the following government schemes:
Energy Company Obligation (ECO)
Great British Insulation Scheme (GBIS)
If it’s faulty you might get problems like damp or mould. You might be able to get it checked and fixed for free.
Check which scheme you used
If you used either ECO or GBIS, Ofgem might have sent you a letter. This letter would explain the potential quality issues with your insulation.
If you’re not sure if you used ECO or GBIS
You might have used ECO or GBIS if both of the following apply to you:
the work on your solid wall insulation was carried out between April 2022 and January 2025
you got help with the cost of the work
If you’re still not sure, contact Ofgem.
Ofgem helpline
Telephone: 0808 169 4447
Monday to Friday, 9:30am to 4:30pm (except bank holidays)
If you need more help, you can contact your local Citizens Advice Bureau or Advice Direct Scotland's energy advice service.
If you didn’t use ECO or GBIS
You might still be able to get your solid wall insulation fixed for free. Check how to complain about an energy efficiency home improvement.
If the insulation was installed on the outside of your home
TrustMark will contact you to offer a free home check. They’ll quote your ‘unique measure reference’ number, so you know they’re genuine.
If you have not been contacted or you’re worried about being scammed you can contact TrustMark to arrange the check.
TrustMark
Telephone: 0333 555 1234
Monday to Friday, 9am to 5pm
Calls to this number can cost up to 16p a minute from a landline, or between 3p and 65p a minute from a mobile (your phone supplier can tell you how much you’ll pay).
You can find other ways to get in touch with TrustMark on their website.
During the home check, a qualified professional will look at the insulation to see if it was installed correctly. If they find any problems, TrustMark should get an installer to fix them. You will not have to pay anything.
If you need more help, you can contact your local Citizens Advice Bureau or Advice Direct Scotland's energy advice service.
If the insulation was installed on the inside of your home
You will not be offered a home check automatically.
You can still contact Ofgem if you’re worried about problems with your insulation. Tell them about the problems and ask them to arrange a home check.
Ofgem helpline
Telephone: 0808 169 4447
Monday to Friday, 9:30am to 4:30pm (except bank holidays)
If you need more help, you can contact your local Citizens Advice Bureau or Advice Direct Scotland's energy advice service.