What FENSA registration actually means when you sell your house

Replacement windows and doors are covered by the Building Regulations, principally for thermal performance, safe glazing, means of escape and ventilation. That means the work has to be signed off by someone.

You can do that through your local authority Building Control, or the installer can be a member of a competent person scheme and self-certify. FENSA is the largest of those schemes and Certass is the other common one. If your installer is registered, they notify the work and a certificate is issued to you and lodged centrally.

When you sell, your buyer’s solicitor asks for evidence that any replacement glazing since April 2002 was properly signed off. If you cannot produce a certificate or a Building Control completion notice, it becomes a query on the sale.

It is rarely fatal, but it is friction at exactly the point you do not want friction. The usual remedies are a retrospective Building Control application or an indemnity policy — both cost money and both take time, and buyers sometimes use it to reopen the price.

Ask whether the company is FENSA or Certass registered in its own name, and ask when you will receive the certificate. It should arrive within a few weeks of completion, without you chasing it.

One thing worth knowing: registration belongs to the company doing the notifying. If the work is subcontracted, ask which company registers it, because that is the one whose name will be on your certificate — and it may not be the one you signed with.

It happens constantly, particularly with work done in the 2000s. You can search the FENSA register for your address to see whether a certificate exists before assuming it does not.

If nothing is recorded and you are replacing those windows anyway, the problem resolves itself: the new installation gets a new certificate, and that is what your buyer’s solicitor is looking for. It is one of the quieter reasons people finally replace windows they had been putting off.

Every installation we carry out is FENSA registered, and our fitters are employed by us rather than subcontracted, so the certificate carries the name of the company you actually dealt with. It sits alongside the 10-year insurance-backed guarantee that covers both the product and the workmanship.