Services
What do window and door defects mean in a survey?
A home survey can see rotten frames, failed glazing seals, distorted openings and windows that no longer keep weather out. Replacement windows in England are often building work. GOV.UK describes competent-person schemes as one way to show compliance, alongside an application. The survey does not certify the installation. It describes the condition.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless a source says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What window problems are actually condition?
Rot in timber, misted double glazing, sills that tip water into the wall, and gaps you can see daylight through are condition. They let heat out and rain in. A survey records them where they can be seen without taking the window out. Misted glass means the seal has failed. It does not mean the frame is rotten, and rotten frames do not always mist the glass.
When are replacement windows a building-regulations question?
In England, replacing windows is commonly building work. GOV.UK explains that a competent-person scheme is one way the installer shows the work met the regulations, and that you can otherwise use a building-regulations application. FENSA is an example of a scheme, not the only route, and this page does not quote a fee for a certificate. Missing paperwork does not, by itself, mean the window will leak. Leaking is what the survey can see. The paperwork is what your solicitor asks the seller for.
- Ask the surveyor which openings are actually failed, not merely dated.
- Ask your solicitor for any competent-person certificate or building-regulations approval.
- Ask whether trickle vents were part of the installation and whether they still open.
What about external doors?
The same split applies. A door that does not close to the frame is weather, security and sometimes a sign the opening has moved. That last point belongs with cracks and lintels. A new door in an old opening still needs a head that carries the wall. The survey is not a locksmith’s report and does not guarantee the ironmongery.
What should you not assume you must replace?
Not every original window. Draughts can be eased and draught-proofed. Rot can be spliced. Failed double-glazed units can be reglazed if the frame is sound. The survey should say which of those it thinks applies. A quote to replace every window because the house is old is not a reading of the report. There is no national window price on this page.
Common questions
Do misted panes mean the whole window must go?
They mean the sealed unit has failed. If the frame is sound, a glazier may be able to replace the glass only. If the frame is rotten or distorted, the survey should say that separately. Do not accept one price that blurs the two.
There is no FENSA certificate. Is the window illegal?
Not necessarily. Competent-person schemes are one route GOV.UK describes. A building-regulations application is another, and older work may predate the scheme you asked about. Your solicitor checks what should exist. The survey tells you if it leaks or has rotted.
Can you replace windows in a listed building?
Often only with consent, and like-for-like is a phrase the council will define, not this page. The survey can say the frames are failing. It cannot grant consent. Ask before you price uPVC for a listed front.
The trickle vents are shut. Does that matter?
They were put there to provide background ventilation. Painted shut or blocked, they stop doing that, and condensation gets more likely. Approved Document F is the England ventilation document for building work. A survey that notes vents are sealed is describing a moisture risk, not a decorating choice.
Does the survey test the locks?
It looks at the leaves and the frames. It is not a security audit and does not guarantee a lock. If security is your question, ask a locksmith. If the door does not meet the frame, ask the surveyor whether the opening has moved.
Are conservatory doors and windows in the same scope?
If the surveyor could see them, they can comment. Conservatories also raise planning and building-regulations questions that belong with the extension page. Condition of the glass is not approval for the structure.
Must single glazing be replaced before you buy?
No. Single glazing is a thermal fact, not a hidden defect. The survey may mention heat loss and condensation risk. Whether you replace it is a comfort and a regulations question for when you do the work, not an automatic condition rating crisis.
What does a new window cost?
No official price is cited here. Size, material, access and whether the lintel needs work change the number completely. Price the openings the survey says have failed, and ask whether making good the reveal is included.
Sources
Key facts
- What the survey sees
- Rot, distortion, failed seals, leaks at the junction with the wall, and whether trickle vents or other background ventilation are painted shut.
- What it does not do
- Certify that a past installation met building regulations, or test every lock.
- Compliance
- GOV.UK: competent-person schemes are one route. A building-regulations application is another. The paperwork is for the solicitor to chase.
- Structure
- If the frame is holding the wall up, read the lintel comments. A new window does not replace a failed lintel.