What is FENSA?

What is FENSA?

FENSA was set up by the Glass and Glazing Federation because from 1st April 2002 all replacement glazing in houses comes under building regulations. The main aim being to ensure that all replacement windows and doors comply to modern insulation standards to save energy and not to ensure good quality work!

As may guess from what FENSA means the building officers don't check every piece of work that a glazing company does. To obtain a FENSA registration a small sample of work by an installer is checked by the a FENSA appointed inspector.

Once an installer is FENSA registered they can certify that the work they have completed is up to Building Regulation standards.

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 local authority approval under the Building Regulations. Local authorities will know of all the approved installers in their areas and will be able to identify unauthorized work very easily. You should note that you, as the house owner, are ultimately responsible for ensuring the work complies with the Building Regulations.

Before you sign a contract to buy replacement glazing, be sure to ask whether the installer is able to self-certify. If not, either they, or you, will need to make an application to your local authority for approval under the Building Regulations and pay the relevant charges.

To summarize a FENSA registered company is useful if your conservatory does need to comply with building regulations as it will mean that they will be able to certify that any work done on your home is up to the standard. But, it does not guarantee good quality or timely work.

Here is the official FENSA site.

"I didn't think fensa covered conservatories anyway."


"we have just had a conservatory built. Do we need to ask for a certificate or will the receipt be enough when we want to move?"


"Do FENSA registered firms need to re-certify at any stage? It seems too easy just to do a good job to satisfy the requirements then go back to doing sloppy work to save a few quid."


"Have been given a quote for new windows by a fitter who works self employed) for a well established and respected double glazing firm in Sheffield. He said if I get my windows by him I'll get a builders certificate which is as good as a FENSA. Is this correct? I know I'll need to produce aa certificate if I sell the house. Many thanks. "

J Berry

"Our conservatory has jist been fitted by a Fensa Registered firm but the workmanship is sub standard is there any thing we can do ?"

Frances Dumbleton