Survey finding
Cornish Unit house: survey, mortgage and what to do
Cornish Unit house mortgage problems follow the standard PRC pattern: unrepaired is rarely mortgageable; certificated repair returns mainstream appetite. This page sets out the variants and the document trail.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Cornish Unit house
What this usually means
Cornish Unit is a precast reinforced concrete (PRC) system built between 1946 and 1955, primarily by the Selleck Nicholls company. Two variants: Type 1 (lower-rise hipped roof) and Type 2 (mansard roof). Designated defective under the Housing Defects Act 1984. Concrete column corrosion is the common defect. PRC Homes Ltd licensed repair is the standard remediation.
Why it matters
Same pattern as Airey and Reema: unrepaired Cornish Unit is not generally high-street mortgageable. Repaired and certificated, mainstream lender appetite returns. Type 1 and Type 2 have slightly different repair specifications, confirm with the engineer.
Ask your surveyor
- Check:Is this Type 1 (hipped) or Type 2 (mansard) Cornish Unit?
- Check:Is there a valid PRC repair certificate?
Ask the seller
- Check:Do you have the PRC repair certificate and structural warranty paperwork?
- Check:When was the repair completed and which contractor delivered it?
Next steps
- •Confirm with your broker which lender will accept this construction type before paying for any further surveys.
- •Order a structural engineer's report if no recent one exists in the property's records.
Tool shortcut
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 previewCross-check this finding with EPC, building age, and address-specific risk data.
What you need to know
Severity
Serious. Lender and insurer involvement likely; structural or specialist remediation.
Typical cost to fix
Licensed Cornish Unit repair: typically £40,000–£80,000 per property. Specialist structural engineer's report £600–£1,500.
Mortgage impact
High-street lenders generally decline unrepaired Cornish Unit. With a valid PRC Homes Ltd certificate, mainstream lenders treat as standard.
Insurance impact
Standard insurance available on certified-repaired Cornish Unit; specialist on unrepaired.
When to pull out
Pull out if unrepaired, no certificate exists. The seller refuses to fund repair, and your lender refuses.
When to renegotiate, and by how much
If certificated, treat as standard. If unrepaired, negotiate by full repair cost plus 15%.
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 previewRead next
PRC (precast reinforced concrete) house , often sits near cornish unit house 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.