Selling a Non-Standard Construction House: A Seller's Guide

If your home was built using anything other than conventional brick or block cavity walls with a pitched, tiled roof, it is likely classified as non-standard construction. This covers a wide range of building methods, from post-war precast reinforced concrete (PRC) council houses to traditional cob and thatch cottages, and from modern timber frame homes to steel-framed properties.

Non-standard construction does not mean your property is defective or unsaleable. Thousands of non-standard homes are sold every year across England and Wales. But the sale process is different from selling a standard brick-and-block house. Your buyer may face restricted mortgage options, their surveyor will need to assess construction-specific risks, and their insurer may have particular requirements. This guide explains what to expect, what to prepare, and how to keep your sale on track.

What counts as non-standard construction?

Non-standard construction is a broad term used by mortgage lenders, surveyors, and insurers to describe any building method that falls outside the conventional approach of brick or block cavity walls on strip foundations, with a pitched roof covered in tiles or slates. The most common types you will encounter include:

If you are unsure of your property's construction type, your title deeds, original planning documentation, or a specialist surveyor can help identify it. Local authority housing departments often hold records for council-built non-standard homes.

PRC designation and repair schemes

PRC houses deserve particular attention because they were built in large numbers across England and Wales during the post-war housing boom, and their construction has specific legal and financial implications for sellers.

The Housing Defects Act 1984 (now consolidated into Part XVI of the Housing Act 1985) designated certain PRC house types as defective because the reinforced concrete components were prone to carbonation and spalling over time. The designated types include Airey, Boot, Cornish Unit, Dorran, Dyke, Gregory, Hamish Cross, Myton, Newland, Orlit, Parkinson, Reema, Schindler, Smith, Stent, Tarran, Underdown, Unity, Waller, Wessex, Wimpey No-Fines, and Woolaway houses.

PRC Homes Ltd was established to administer approved repair schemes for these designated dwellings. The typical repair involved stripping the original concrete panels and overcladding the structural frame with conventional brick or insulated render. Properties repaired under an approved scheme receive a PRC certificate of completion, which confirms the repair meets the approved standard. This certificate is essential for obtaining a mortgage on a repaired PRC property.

If your property is a PRC type that has not been repaired, most mainstream mortgage lenders will decline to lend. This limits your buyer pool to cash purchasers and specialist investors, which typically reduces the sale price significantly. If repair is feasible before selling, obtaining the PRC certificate of completion will open up your market considerably.

Mortgage availability for non-standard construction

The buyer's ability to obtain a mortgage is often the most significant factor in selling a non-standard construction house. Each lender has its own criteria for what construction types it will accept, and these are set out in the UK Finance Mortgage Lenders' Handbook. The buyer's solicitor will check these requirements as part of their conveyancing enquiries.

In general terms, mortgage availability follows this pattern:

• Widely mortgageable: Timber frame (modern and traditional), steel frame in good condition, repaired PRC with completion certificate, and Wimpey No-Fines with satisfactory cladding.
• Mortgageable with specialist lenders: Cob and thatch (building societies with local knowledge), BISF steel frame (some mainstream and most specialist lenders), and concrete panel systems in good condition.
• Very difficult to mortgage: Unremediated PRC designated types, Mundic block that has failed Stage 2 testing, and properties with significant structural defects regardless of construction type.

A mortgage broker experienced in non-standard properties is often the most efficient route for your buyer. Brokers have access to the full market, including specialist lenders and building societies that do not appear on comparison websites. Recommending that your buyer speaks to a broker early in the process can prevent delays and reduce the risk of a sale falling through due to mortgage difficulties.

Survey requirements: why a full building survey matters

For non-standard construction, a RICS Level 3 Building Survey is strongly recommended over a Level 2 HomeBuyer Report. The Level 2 survey is designed for conventional properties in reasonable condition. Its scope does not extend to a detailed assessment of non-standard structural elements, specialist materials, or construction-specific defects.

A Level 3 Building Survey provides a thorough investigation of the building's fabric and structure, including:

• Assessment of the structural frame (concrete, steel, or timber) for corrosion, carbonation, decay, or movement
• Inspection of cladding, panel joints, and weatherproofing systems
• Evaluation of insulation, ventilation, and moisture management \u2014 critical in timber frame and PRC properties
• Identification of construction-specific defects such as concrete spalling, steel corrosion, or timber rot
• Comment on the property's suitability for mortgage purposes

Many mortgage lenders will insist on a full building survey for non-standard properties before approving a loan. As a seller, you cannot control which survey your buyer commissions, but you can prepare by ensuring the property is accessible for inspection and that you have any existing survey reports, repair certificates, or structural assessments ready to share.

If the survey raises concerns, the buyer may seek to renegotiate the price or request that you carry out repairs before completion. Being prepared for this possibility and understanding the likely findings for your construction type will help you respond effectively.

Insurance challenges for non-standard homes

Buildings insurance is a prerequisite for any mortgage, and non-standard construction can make obtaining suitable cover more complicated. Standard comparison websites may not return results for your property type, and some mainstream insurers have blanket exclusions for certain construction methods.

The main insurance challenges by construction type include:

• Thatched roofs: Higher fire risk means significantly higher premiums. Insurers typically require evidence of regular thatch inspections and may impose conditions about chimney sweeping, electrical wiring, and fire separation. Premiums for thatched properties can be two to three times higher than for conventional roofs.
• PRC and concrete panel: Insurers may require confirmation that the property has been repaired under an approved scheme. Unremediated PRC may face higher premiums or exclusions relating to the concrete structure.
• Timber frame: Generally insurable at competitive rates, but insurers may ask about fire stopping, damp-proof measures, and the condition of the timber structure.
• Cob walls: Specialist cover is needed because cob is vulnerable to water ingress. Insurers may require confirmation that the walls are properly limewashed or rendered and that the thatch overhang protects them from rain.
• Mundic block: Insurers will want to see a passing Mundic test certificate. Properties that fail the test may struggle to obtain cover at any price.

The British Insurance Brokers' Association (BIBA) maintains a panel of specialist brokers who can source cover for non-standard properties. As a seller, confirming that your own buildings insurance is active and providing a copy of your policy schedule to the buyer's solicitor can prevent delays during conveyancing.

Council-built non-standard homes

A significant proportion of non-standard construction houses in England and Wales were originally built by local authorities during the post-war period to address the housing shortage. Many of these were subsequently sold to tenants under the Right to Buy scheme introduced by the Housing Act 1980.

If you purchased your property through Right to Buy or from a subsequent owner who did, you may have documentation from the original sale that identifies the construction type. Local authority housing departments often hold records of their non-traditional housing stock, including which properties have been repaired under approved PRC schemes.

Former council properties can carry additional considerations for buyers beyond the construction type, including service charges if the property is on an estate with communal areas, and the design and layout typical of mass-built social housing. However, the construction type is usually the most significant factor affecting mortgage availability and insurance.

Disclosure on the TA6 Property Information Form

Your TA6 Property Information Form requires you to provide information about the property's construction. You must disclose the construction type honestly and provide any relevant documentation. Concealing non-standard construction could expose you to a misrepresentation claim under the Misrepresentation Act 1967.

Beyond the TA6, your broader duty of disclosure means you should not conceal or misrepresent any aspect of the property's construction, condition, or history. This includes:

• The construction type and any designation (for example, PRC designated under the Housing Defects Act 1984)
• Any repairs or remediation carried out, with certificates and completion records
• Known defects or ongoing issues related to the construction method
• Any specialist surveys or reports that have been carried out
• Insurance claims related to the construction type

Thorough disclosure is not just a legal obligation \u2014 it is a practical way to build buyer confidence and prevent the kind of surprises during conveyancing that cause sales to fall through.

BSI PAS 2035 and energy efficiency retrofits

BSI PAS 2035:2019 is the specification for retrofitting domestic buildings to improve energy performance. It is particularly relevant to non-standard construction because these properties often have different thermal, moisture, and ventilation characteristics compared to standard brick-and-block homes.

If your property has undergone energy efficiency improvements \u2014 such as external wall insulation, internal wall insulation, or cavity fill \u2014 the work should have been carried out in accordance with PAS 2035 if it was funded by a government scheme such as the Energy Company Obligation (ECO) or the Green Homes Grant. PAS 2035 requires a proper pre-assessment of the building's fabric, a moisture risk assessment, and a ventilation strategy before any insulation work is carried out.

Retrofit work carried out without proper assessment can cause serious problems in non-standard construction, including:

• Interstitial condensation in timber frame walls caused by incorrectly installed insulation
• Trapped moisture in PRC panels leading to accelerated carbonation of the concrete
• Damp and mould caused by inadequate ventilation after draught- proofing measures
• Structural damage from failed cavity wall insulation in properties where cavity fill was not appropriate for the construction type

If retrofit work has been carried out on your property, having the PAS 2035 assessment, installation certificates, and any guarantees available for the buyer's surveyor is important. If the work was not carried out to PAS 2035 standards, the buyer's surveyor may flag it as a concern.

Pricing considerations

The price impact of non-standard construction depends on several factors:

• Construction type and condition. Timber frame and steel frame properties in good condition may sell at or close to the price of comparable standard-construction homes. Unremediated PRC or failing Mundic block can reduce the price by 15% to 30% or more.
• Mortgage availability. If the property is mortgageable with mainstream lenders, you retain access to the widest buyer pool. If only cash buyers or specialist lenders can finance the purchase, expect a discount.
• Local familiarity. In areas where a particular construction type is common \u2014 Mundic block in Cornwall, cob in Devon, timber frame in Scotland and the Borders \u2014 buyers and their advisers are more familiar with the issues and less likely to be deterred.
• Documentation quality. Comprehensive documentation including repair certificates, survey reports, and insurance records supports your asking price. Missing records create uncertainty and give buyers leverage to negotiate.
• Remediation status. A PRC property with an approved repair certificate is worth significantly more than the same property without one. The cost of PRC remediation typically ranges from \u00a315,000 to \u00a340,000 depending on the house type and the scope of the work, but the increase in sale price usually exceeds the cost.

Discuss pricing with your estate agent and be transparent about the construction type. An experienced local agent will understand how non-standard construction is viewed by buyers in your area and can set a realistic asking price.

Practical steps to prepare for your sale

If you are selling a non-standard construction house, follow these steps before listing to give yourself the best chance of a smooth transaction:

1. Confirm your construction type. Check your title deeds, any original purchase documentation, and your local authority's housing records. If you are still unsure, commission a specialist survey to identify the construction method.
2. Gather all relevant certificates and reports. This includes PRC repair certificates, Mundic test results, structural survey reports, timber treatment certificates, and any documentation relating to past remedial work.
3. Check your buildings insurance. Confirm that your policy is active and that it covers the construction type adequately. Obtain a copy of your policy schedule and claims history to share with the buyer's solicitor.
4. Complete your TA6 form thoroughly. Disclose the construction type and provide cross-references to your supporting documentation. Our guide on what to disclose when selling covers your obligations in detail.
5. Instruct your solicitor early. Brief them on the construction type and provide your documentation pack before you accept an offer. They can anticipate the enquiries that will be raised and prepare responses in advance.
6. Consider a pre-sale survey. For properties where the construction type is likely to raise significant buyer concerns \u2014 such as PRC, Mundic block, or older steel frame \u2014 commissioning your own specialist survey before listing can identify issues and demonstrate transparency.

Sources and further reading

• Royal Institution of Chartered Surveyors (RICS) \u2014 Guidance on the survey of non-traditional housing and the Mundic testing protocol: rics.org
• Building Research Establishment (BRE) \u2014 Information Papers on non-traditional housing types and defects, including BRE Good Building Guide series: bregroup.com
• Housing Act 1985, Part XVI \u2014 Legislation on defective housing (PRC designation): legislation.gov.uk
• BSI PAS 2035:2019 \u2014 Retrofitting dwellings for improved energy efficiency: bsigroup.com
• UK Finance \u2014 Mortgage Lenders' Handbook, individual lender requirements for non-standard construction: lendershandbook.ukfinance.org.uk
• British Insurance Brokers' Association (BIBA) \u2014 Find a specialist broker for non-standard property insurance: biba.org.uk
• Gov.uk \u2014 Right to Buy scheme guidance and council housing records: gov.uk/right-to-buy-buying-your-council-home
• Law Society \u2014 TA6 Property Information Form guidance notes: lawsociety.org.uk

Frequently asked questions