Reducing the amount of heat lost from your home, for example by adding more insulation, can reduce energy use and bills.

Installing more efficient heating appliances, heating controls or hot water storage equipment can also reduce energy use.

The installation of such energy efficiency measures in the home is called "Retrofit".

To minimise cost and disruption, a good time to consider retrofit options, is when making other improvements to your home, such as an extension.



If you are having work done on your home, there are a number of certification routes designed to protect consumers:

  • TrustMark is the Government endorsed quality scheme that covers work a consumer chooses to have carried out in or around their home. Find a detailed guide to retrofitting your home and a retrofit guidance app which can be downloaded to mobile phones, on the Trustmark website.
  • The PAS:2035 standard had been created to manage the home retrofit process by installers certified to PAS:2030. Look for installers that are accredited to this standard.
  • All renewable technologies, such as heat pumps and solar panels, as well as installers of these technologies, should be Microgeneration Certification Scheme (MCS) certified. Find a list of certified installers on the MCS website.
  • The Cavity Wall Insulation Self Certification scheme (CWISC) provides homeowners with the comfort of knowing that work by registered contractors complies with the requirements of the Building Regulations. Learn more about the CWISC scheme.
  • The Cavity Insulation Guarantee Agency (CIGA) provides independent 25 year guarantees for cavity wall insulation fitted by registered installers. Visit their website to find out more.


Some measures, such as solar panels, air source heat pumps, external wall insulation and double glazing, may require planning or building control approval. This can add time and cost to the project, so make sure to consider this at an early stage. Check planning requirements on the planning portal.

Skills and Training 

For help with retrofit qualifications and training, as well as details of retrofit events, check the South London Retrofit Skills website.