Replacing windows

All replacement glazing falls within the scope of the building regulations. Anyone who installs replacement windows or doors will have to comply with strict thermal performance standards.

One of the main reasons for this to reduce energy loss. It is essential to improve the performance of existing buildings if we are to meet increasingly stringent national and global energy saving targets.

When you sell your property, your purchaser's surveyors will ask for evidence that any replacement glazing installed after April 2002 complies with the new building regulations. There are 2 ways to prove compliance:

  • have a certificate showing that the work has been done by an installer who is registered under the FENSA scheme
  • have a certificate from the council saying the installation has approval under the building regulations

The FENSA Scheme

A sample of the work of every installer will be inspected by FENSA appointed inspectors to ensure standards are maintained. FENSA will also inform councils of all completed FENSA installations and issue certificates to householders confirming compliance.

Any installation done by a firm which is not registered to self-certify or done as a DIY project by a householder will need full council approval under the building regulations. Councils will know of all the approved installers in their areas and will be able to identify unauthorised work very easily. Be aware that the home owner is responsible for ensuring the work complies with the building regulations.

Before signing a contract to buy replacement glazing, ask whether the installer is able to self-certify. If not, either they or you will need to make an application to your council for approval under the building regulations and pay any relevant charges.

There may be conditions or other additional controls on your property which restrict the types of windows you can install.

There is also information at the Glass and Glazing Federation.


Last updated: 28 November 2016
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