Windows, doors and glazing
A competent-person certificate exists for the windows and the frames are rotten. Why does the certificate not describe today's condition?
The certificate does not describe today's rotten frames because it records the installation route, not the timber now. A competent-person certificate is one route to building-regulations compliance when the windows were put in. The survey does not issue that certificate and has not rechecked the work. Rot is a condition finding from this visit. The paper does not refresh itself as the wood decays, and it does not call the frames sound today. Keep the certificate for the solicitor. Read the rot as a separate defect the certificate never claimed to describe.
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?
A competent-person certificate speaks about how the replacement was notified at the time, not about the frames years later. Water sitting in a joint, a sill or a bottom rail can start decay after a regular installation. The certificate is not a second look at softness, staining or opened joints. Those points come from the inspection. Both facts can stand together: paperwork for the original work, and rotten timber found on the day of the visit.
Give the certificate to the solicitor with the questions of which windows it names and whether any later replacement is missing from it. Ask a joiner to separate tired decoration from timber that has lost its section, and to say whether the rot is local to the sill or has reached the jamb. The survey has not designed that repair and has not issued a building-regulations certificate for any future replacement.
What should you ask your surveyor?
- Which windows does the certificate actually name?
- Has the rot reached the jambs or only the sills?
- What should a joiner open before pricing the frames?
What are the typical next steps?
- Send the certificate to the solicitor and ask which openings it covers.
- Ask a joiner to probe the rotten timber and mark sound wood.
- Keep the rot finding and the certificate as two separate papers.
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
Does the same certificate prove the sealed units are still sound?
No. A competent-person certificate is about the installation route, not a check that every cavity between the panes is still dry. Mist, failed seals and rotten frames are condition points from the visit. The survey has not tested the glass and has not treated the certificate as a cleanliness or seal report on today's units.
Who chases a building-regulations application if the certificate misses a later window?
The solicitor chases that paper. A competent-person scheme is one route and a building-regulations application is another. The survey does not issue either, and it does not choose which route was used for a window the certificate does not name. Missing paperwork is a legal question beside the rotten timber the visit could see.