Survey finding
Single glazing on your survey: replacement vs upgrade
Single glazing is a Cat 1 informational flag. This page covers the realistic upgrade options.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Single glazing condition
What this usually means
Single-glazed windows are common in older and listed properties. The flag is informational: high heat loss, cold and noisy. Replacement options range from secondary glazing to full window replacement (subject to listed/conservation rules).
Why it matters
Comfort, running costs, and EPC band.
Ask your surveyor
- Check:Is the window timber sound?
- Check:Is the property in a conservation area?
Ask the seller
- Check:Have any windows been replaced?
- Check:What's the heating bill in winter?
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.
Tool shortcut
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What you need to know
Severity
Cosmetic. Note for budget but not a negotiation lever in itself.
Typical cost to fix
Secondary glazing £400-£1,000 per window. Full timber replacement £1,200-£2,500. Listed-grade slim-profile double glazing £1,500-£3,000+.
Mortgage impact
Standard.
Insurance impact
Standard.
When to pull out
Not relevant.
When to renegotiate, and by how much
Whole-house replacement budget if intending to upgrade; typical 1-3% off.
Thinking of pulling out or renegotiating? What to do after a bad survey
Run the check on this address
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.
Run the check
Check the property before you offer
Flood, subsidence, EPC, crime, schools, transport, broadband, tenure, age, listed status and price checks where data is available.
Run a free previewHow 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.