Windows, doors and glazing
One replacement window has no FENSA certificate in the pack. Is that window unlawful, or is the certificate only one route under the competent-person schemes?
The missing FENSA certificate does not make that replacement window unlawful. Competent-person schemes are one route to building-regulations compliance, and FENSA is one such scheme, not the only route. The survey has not produced a certificate, and none for this window was in the pack. A council application is another route that can exist. The inspection records the window it could see. It does not issue the paperwork, and a missing scheme certificate is not a verdict that the window fails the law.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Replacement windows are building work. One way of showing compliance is a certificate from a competent-person scheme, of which FENSA is an example. Another way is an application to building control. The pack lacking a FENSA sheet for one window means that particular certificate was not there to read. It does not mean no other paper exists, and it does not mean the survey has tested the installation. Approved Document A is structural guidance. It is not a certificate for this window, and the survey has not issued one.
Ask the solicitor to request the paperwork for that window: a scheme certificate, a building-control completion, or an explanation of which route was used. A missing sheet is a documents question. The survey can still comment on how the window looks, if it did. Do not tell the seller the window is outside the law. Say the certificate they might have expected was not in the pack, and ask what route was used.
What should you ask your surveyor?
- Did you see a certificate for this window, or only its absence from the pack?
- Have you treated FENSA as one scheme, not the only route?
- What did you actually observe about the window itself?
What are the typical next steps?
- Ask the solicitor for the compliance paper for this window.
- Do not treat a missing FENSA sheet as the only possible route.
- Keep the survey description separate from the certificate.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If building control signed the work instead, is that a different route?
Yes. A building-control completion is a different route from a competent-person certificate. The survey has not seen that paper either, unless it was in the pack. The point stands: one missing FENSA sheet does not close every route, and the survey still has not issued a certificate.
Does a missing certificate mean the glass has failed?
No. Paperwork and the condition of the glass are different. The survey has not called the unit failed because a certificate was absent. Look at what the report says about the glass, the frame and the seals. Absence of FENSA is not a misted unit.