Who are FENSA?
FENSA stands for the Fenestration Self-Assessment Scheme. It was set-up by the Glass and Glazing Federation (GGF) as a governing body for the double glazing industry.
Around 9,000 companies are registered with FENSA, who assess each company individually to ensure the Building Regulations are being met.

Even when a company joins FENSA they can still be spot checked by an independent inspection body.
FENSA protects customers from cowboys, by reporting rogue traders to local authorities and withholding membership if applicants do not meet the criteria.
It’s a criminal offense to claim you’re registered with FENSA if it’s not true, under the Trade Marks Act 1994 and Consumer Protection from Unfair Trading regulations 2008.
Energy efficient windows and doors will also receive FENSA certificates to prove their thermal performance, which encourages homeowners to think about the environment during an installation.
The FENSA certificate is issued if the new installation complies with Building Regulations and could be vital if you’re looking to sell your house.
And if you lose your certificate it’s very easy to reorder from the FENSA website.
An installer registered with FENSA must:
- Provide a deposit protection service
- Give homeowners a 5-10 year guarantee on new windows and doors
- Offer an insurance backed guarantee.