Survey finding
Skylight or roof light condition: what it means and what to do
Skylights are common on loft conversions and modern roof designs. This page covers when skylight findings matter, what replacement costs, and how to handle the negotiation.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Skylight or roof light condition
What this usually means
Skylights and roof lights (Velux is the dominant brand but generic name skylights are common) are sealed glazed units in a pitched or flat roof. Failure shows as condensation, leaks at the flashing, motor failure on opening units, or seal failure on the glazing. Lifespan is typically 15–25 years for non-opening units; less for opening ones with motors.
Why it matters
A leaking skylight causes localised internal damage. The fix involves both the unit and the flashing kit, often as a single replacement. Lenders rarely refuse but may want documented repair if combined with wider roof issues.
Ask your surveyor
- Check:Is the failure at the unit, the flashing, or both?
- Check:Is the underlying timber and felt around the unit sound?
Ask the seller
- Check:When was the skylight installed?
- Check:Have any leaks or repairs been carried out?
Next steps
- •Get two written quotes from local trades before negotiating with the seller.
- •Speak to your mortgage broker before exchanging if the finding affects mortgageability.
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What you need to know
Severity
Maintenance item. Worth quoting and including in negotiation.
Typical cost to fix
Replace a single Velux unit with flashing kit: £600–£1,200 supply and fit. Larger or specialist units £1,500–£3,500. Specialist conservation roof lights for listed buildings: £2,500–£6,000+.
Mortgage impact
Standard for most lenders.
Insurance impact
Storm or impact damage typically claimable. Seal failure is wear-and-tear.
When to pull out
Never a pull-out trigger in isolation.
When to renegotiate, and by how much
Get a roofer's or specialist installer's quote. Negotiate on quote plus 15%.
Thinking of pulling out or renegotiating? What to do after a bad survey
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The Survey Decoder explains the wording. The full report adds address-specific flood, subsidence, EPC, crime, listed status, building age and price comparison data, so a single finding isn't judged in isolation.
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Flood, subsidence, EPC, crime, schools, transport, broadband, tenure, age, listed status and price checks where data is available.
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Roof issues , often sits near skylight or roof light condition on a survey and is the next thing to check.
How MyPropertyScan produces this guide, and what it is not
Published by MyPropertyScan and written by Ziad Nasr, who is accountable for its accuracy. No page here is written or reviewed by a chartered surveyor, conveyancer or regulated adviser, and we do not claim otherwise.
This page is not:
- Chartered surveying — we do not inspect properties or produce RICS Home Survey reports
- Legal advice — we do not act as conveyancers or advise on title, tenure or contracts
- Mortgage or insurance advice — we are not regulated by the FCA and give no recommendations
Figures and process steps come from the published UK datasets and standards listed on this page, not from professional practice. Pages are updated when source coverage, survey cost assumptions, or lender and legal requirements materially change. Dataset limitations are set out on the methodology page.
Spotted something out of date or wrong? Email hello@mypropertyscan.com and we will correct it and change the update date.
Sources used
We use UK public and specialist sources where they are available. Public datasets can be incomplete, delayed, or missing for some addresses. Treat them as a starting point, not as a replacement for professional advice.
Source standard: preference goes to official government datasets, statutory bodies, professional standards, and primary dataset publishers. We cite the source family on the page and explain coverage limits rather than filling gaps with unsupported estimates.
- Professional standard: RICS Home Survey StandardRICS standard for condition-based residential surveys in the UK.
- Learn more from: RICS consumer guide to surveysConsumer-facing guide to survey types and when each level is appropriate.
- Official guidance: GOV.UK buying or selling your homeGovernment overview of the home buying and selling process.