Buying a Concrete House: Mortgages, PRC Defects and Conveyancing Tips
If you are eyeing up a concrete house, you are stepping into a complex legal and financial landscape. In the UK property market, a concrete house is classified as non-standard construction. Falling blindly in love with one without doing your due diligence can lead to your mortgage being rejected, your building insurance being denied, or leaving you with an unsellable home.
Whilst a concrete built property is potentially a non-starter if you have a conventional high-street mortgage, there are potentially ways of progressing without simply buying for cash. By understanding the strict legal frameworks, following the appropriate mortgage requirements, securing the right structural guarantees, and deploying the correct RICS surveys, you could safely navigate the purchase and unlock an incredible, affordable investment.
Concrete house construction: Systems and post-war methods
A concrete house is a residential property where the load-bearing walls are constructed from concrete rather than using two primary methods:
- Pre-cast reinforced concrete (PRC): Factory-made, dense, and heavily-weighted concrete foundation.
- In-situ poured concrete: Liquid concrete poured directly into temporary timber or steel moulds (known as formwork or shuttering) built on-site around an internal grid of steel reinforcing bars.
The Housing Act 1985
Under Section 528 (1) and (2) of the Housing Act 1985, the government officially designated over 30 specific types of prefabricated concrete houses, including Wates, Airey, Cornish, Woolaway, and Reema designs, as inherently defective. This statutory declaration means that by law, these properties are considered structurally flawed due to the rapid degradation of their materials.
Source: Housing Act 1985.
Critical risk factors: Mortgages, insulation, and structural integrity
As a buyer, identifying whether a property is a concrete house dictates your entire financing, legal, and insurance strategy. Mistaking a concrete property for a standard brick home carries severe consequences:
- The mortgage valuation trap: You might secure a standard Mortgage in Principle based purely on your income. However, during the formal purchase process, the lender will instruct a desk valuation or physical valuation survey. The moment the valuer identifies a non-standard concrete build, they assess it against strict risk criteria. If it fails, they will flag the property as unsuitable security, instantly revoking your mortgage offer.
- High-street mortgage refusal and LTV drops: Mainstream high-street lenders view unremediated concrete houses as high-risk liabilities. Even if a specialist lender agrees to offer a mortgage on a repaired concrete home, they will drastically adjust the loan terms. While a standard brick home allows for a 5% to 10% deposit, a concrete house valuation often forces a drop in the maximum Loan-to-Value (LTV) down to 75% or even 60%, requiring you to find a massive cash deposit to bridge the gap.
- Extreme thermal bridging: Unlike modern cavity-wall brick homes, older concrete panels offer terrible thermal insulation. Without specialised external wall insulation, these homes suffer from severe cold bridging, leading to heavy internal condensation and toxic black mould.
- Reinforcement degradation (carbonation): Unlike brick, unsealed concrete is highly porous. It absorbs atmospheric moisture and carbon dioxide over decades, leading to a chemical process called carbonation. Once moisture penetrates the core, it triggers rust on the internal steel. As the steel corrodes, it expands up to three times its original size, fracturing the concrete framework from within.
How do mortgage valuers categorise concrete properties?
When a surveyor conducts a mortgage valuation on a concrete home, they categorise the property into one of three distinct risk brackets that dictate if a bank will lend:
- Category A: The property type is well-established, structurally sound, and mortgageable in its original, un-remediated condition (e.g., certain Laing Easiform or Wimpey No-Fines builds).
- Category B: The property is acceptable to lenders only following an approved, government-licensed scheme of structural repair backed by a valid PRC Certificate.
- Category C: The lender rules the property inherently defective, high-risk, and completely unmortgageable.
Where the surveyor flags that the property is built of concrete, they will usually include within their report a qualification requiring the buyer to instruct a specialist surveyor or structural engineer to inspect the concrete and confirm its condition. Pending this inspection, the valuer will typically return a 'nil valuation' (£0) to the lender. The lender will require this satisfactory report before they agree to revise the valuation and issue a formal mortgage offer.
The 4-step legal and conveyancing path to buying a concrete home
The conveyancing and legal process for a concrete house requires a rigorous, multi-step validation path that differs significantly from a standard transaction.
Identify the exact concrete house type
Before making an offer, review the estate agent listing or ask the seller to confirm the exact architectural system name (e.g., Airey, Cornish, Reema).
Verify the PRC Certificate via your solicitor
During the conveyancing search phase, your solicitor must check the property deeds for a formal PRC Certificate of Structural Repair. This certificate confirms that the house has undergone a licensed, government-approved repair scheme in which concrete panels were removed and replaced with a traditional brick skin.
Instruct a RICS Level 3 Building Survey
Commission an experienced surveyor to perform an intrusive structural assessment. If the property is located in Cornwall or Devon, you must also order a specialised Mundic Block Test to ensure the aggregate isn't degrading into dust due to historic mining waste components.
Expert Tip: The survey must be intrusive
When a surveyor cannot adequately satisfy themselves with the condition of the concrete, then it is imperative that they undertake an intrusive inspection. As a whole, a Level 3 Home Survey is non-intrusive, meaning the surveyor looks for visible defects but doesn't go beyond the surface.
Do adequately answer if the property's concrete structure is in good condition, the surveyor will need to drill holes into the concrete to inspect the middle. The issue with this is the surveyor doesn't make good the drill holes, and the seller must give their consent prior to the inspection.
CEO of SAM Conveyancing
Source a specialist non-standard lender
Provide the RICS report and PRC Certificate to a specialist mortgage broker to target non-standard construction mortgage lenders who explicitly accept repaired concrete homes.
Budgeting for specialist surveys and concrete material tests
Because a concrete house is a non-standard construction, a standard RICS Level 2 Survey is completely inadequate because it is purely visual and non-intrusive. You must budget for deeper, structural investigations.
Expert Tip: Avoid a hidden financial trap
If you are buying a flat within a concrete high-rise or low-rise block, you face a hidden financial trap: The Section 20 Notice. In the 1970s, High Alumina Cement (HAC) was banned due to sudden structural collapses, so if a building is found to contain HAC or modern Reinforced Autoclaved Aerated Concrete (RAAC), the freeholder is legally obligated to carry out remediation works. Under a Section 20 leasehold consultation, the freeholder can pass those structural remediation costs directly to leaseholders. A seemingly cheap £120,000 flat can instantly come with a mandatory £40,000 service charge bill for structural concrete repairs. Always have your solicitor demand the full block testing history from the freeholder.
CEO of SAM Conveyancing
Survey/test type | Average cost | Strategic purpose and necessity |
|---|---|---|
RICS Level 3 Building Survey | £600 – £1,200+ | Evaluates overall structural integrity, identifies internal reinforcement rust, and checks for historic structural movement. |
Mundic block core drilling | £400 – £800 | Mandatory in the South West. Drills core samples to analyse if mining waste aggregate is causing structural rot. |
Intrusive engineer inspection | £500 – £1,500 | Required if the RICS surveyor finds internal concrete cracking and needs to inspect the core reinforcement framework directly. |
How long does purchasing a concrete home take?
A concrete house purchase typically takes 8 to 12 weeks, which is roughly 2 to 4 weeks longer than a standard brick property transaction due to the extra legal verification required.
Expert Tip: Speed up the process
To expedite the process and prevent your mortgage offer from being delayed, do not wait for the lender to ask for paperwork. The moment your offer is accepted, instruct your seller to hand over the PRC Certificate of Structural Repair and the original building control completion certificates.
Hand these directly to your conveyancing solicitor and mortgage broker on day one. If the seller cannot produce these documents, you can immediately pivot to sourcing a specialist indemnity insurance policy or renegotiating the purchase price down to reflect the cost of future remediation.
MSc, BSc (Hons), AssocRICS Surveyor
Your concrete house action plan
Before speaking to an adviser, tick off these essential steps:
- Check the construction type: Confirm whether the property is a designated PRC defective type (Airey, Wates, Cornish, etc.).
- Locate the PRC Certificate: Ensure a valid structural repair certificate is fully logged with the property deeds.
- Book a RICS Level 3 Survey: Hire an experienced surveyor who specializes in 20th-century non-standard construction.
- Request freeholder logs (For Flats): Secure written confirmation that the block has been tested for High Alumina Cement (HAC) and RAAC.
- Run a Mundic Test: Ensure a core test is completed if the property is located in Devon or Cornwall.
- Match with a specialist lender: Filter out high-street lenders and apply only to those with clear non-standard construction lending criteria.
Don't let hidden defects ruin your moving day
Concrete properties require a specialist eye. From Mundic issues to hidden reinforcement corrosion or leaking tanks, non-traditional builds carry unique risks that standard valuations completely miss.
Ensure your property is mortgageable and structurally sound with a specialist RICS Home Survey.
Frequently asked questions about CCJs
Andrew Boast FMAAT is a qualified accountant, conveyancing specialist and author with over 25 years of experience in the UK property sector. Since beginning his career in 2000 within established SRA and CLC-regulated conveyancing solicitor firms, Andrew has overseen the legal journeys of more than 75,000 clients.
He is the self-published author of the first-time buyer guide: How to Buy a House Without Killing Anyone, and a frequent contributor to mainstream UK media on legislative updates, property law, first-time buyer guides, conveyancing best practices, and stamp duty changes. Andrew specialises in resolving complex title issues, property conflict disputes, and property tax options, streamlining the enquiry process to reduce transaction times and maintaining a client-friendly focus.
Amanda Ambler is a highly accomplished conveyancing specialist with over 15 years of dedicated experience across residential property law, legal compliance, and practice management. Having held senior roles, including Head of Legal Practice and Head of Conveyancing at established UK law firms, Amanda possesses a profound, hands-on understanding of the technical intricacies of the property market.
As the designated Legal Content Reviewer for SAM Conveyancing, Amanda ensures that every guide, legal update, and resource published meets the absolute highest standards of accuracy, regulatory compliance, and factual integrity. Her rigorous review process guarantees that complex property legislation and industry processes are communicated clearly, transparently, and safely for home buyers and sellers alike.
