How to Sell an Unmortgageable Property: What Lenders Refuse and Your Options

What “unmortgageable” means

People use the word for a house that buyers needing a mortgage struggle to buy, because lenders will not lend on it or will lend only after a repair or a specialist report. It is a label, and each lender decides for itself. The cases below each come from a body that publishes the detail. They are examples, and the list is not complete.

Concrete-panel (PRC) houses

BRE, the building research body, says tens of thousands of precast reinforced concrete (PRC) properties remain and that structural repairs are needed because of concrete carbonation. It adds that mortgage lenders show a reluctance to continue to lend on these properties, or to offer home insurance, and that bad repairs can threaten an owner’s ability to get a mortgage.

The BRE Global repair scheme has registered repair specifications for four PRC house types: Airey, Reema, Underdown/Winget and Wates. It does not currently cover other PRC types, and its first certificate was issued in July 2016, so older repair certificates did not come from this scheme.

Flats and external wall cladding

RICS describes the EWS1 form as a set way for a building owner to confirm to lenders and valuers that an external wall system has been assessed for safety by a suitable expert. RICS is clear that it is not a life safety certificate.

RICS also reports data collected by the government from lenders. It shows that the majority of mortgage valuations for flats do not require an EWS1 form or equivalent. For buildings of seven storeys and above, 48% of valuations by five lenders did require one in April to June 2024, down from 62% a year earlier.

Japanese knotweed

The Property Care Association says a property where knotweed is considered a risk can be controlled by a management plan. To meet the lender’s requirements, it says, the plan and its execution need to be carried out by a member of a recognised trade association, such as the Property Care Association itself.

Short leases

GOV.UK’s plain-English explainer on extending a lease says the new law removes “marriage value” costs, cutting the price significantly for leases with 80 years or fewer remaining. Whether that applies to your lease, and what a buyer’s lender will accept, are questions for a solicitor who knows leasehold.

Ways to sell an unmortgageable property

Fix the problem and sell on the open market. The sources above describe the fixes: a certified repair for the PRC house types the BRE scheme covers, a knotweed management plan from a recognised trade association member, or a lease extension. Get the quotes first, then compare the cost with the discount a buyer would ask for.

Sell to a buyer who does not need a mortgage. That means an auction, a cash buyer or a property buying company. See six ways to sell a house fast for who oversees each route.

Selling an unmortgageable property at auction

The Property Ombudsman says traditional auctions tend to attract cash buyers. At a traditional auction the property sells to the highest bidder who meets the reserve, the sale is unconditional and contracts are exchanged immediately. The buyer pays a 10% deposit, and completion is usually 28 days later or the period in the legal pack.

The reserve is a confidential minimum you agree with the auctioneer, and the property sells only if bidding reaches it. The Ombudsman tells sellers to check auction house fees in advance, including seller’s fees and administration charges. It gives no amounts.

At a modern method auction the highest bidder signs a reservation agreement and pays a reservation fee. The Ombudsman says this method is more accessible to buyers who need a mortgage, which makes it a poorer fit if lenders will not touch the property.

Selling to a cash buyer: checking the cash offer

Expect a cash offer below market value, and compare it with what you would keep after fees using the cost of selling worksheet. Check the company before you talk to it with questions to ask a cash house buyer. Our problem property page covers the cash route.

The Property Ombudsman’s Code of Practice for Residential Property Buying Companies says a member confirms any change to its offer in writing promptly, and does not reduce the price late without a valid reason explained in writing (clauses 4h and 4i). The code binds members only, so check the company is on the Ombudsman’s register before you rely on it.

What to tell the buyer

Whatever the route, the problem has to be disclosed. Answer the Law Society’s TA6 questions truthfully, and say so where you do not know. Selling a house as is sets out what you still have to tell buyers. For how the routes compare on speed and cost, see how to sell a house fast.

FAQ

Why is a house unmortgageable?

Lenders decide for themselves. Published examples include PRC concrete construction, flats where an external wall safety assessment is needed, and Japanese knotweed without a management plan from a recognised trade association member.

Can I sell an unmortgageable property at auction?

Yes. The Property Ombudsman says traditional auctions tend to attract cash buyers, and that the sale is unconditional once the hammer falls. Check the auction house’s fees in advance and agree a reserve with the auctioneer.

Who buys unmortgageable properties?

Cash buyers, including those at traditional auctions, as the Property Ombudsman describes. Check any buying company on the Ombudsman’s register of businesses and ask for proof of funds before you agree anything.

Are all properties of non-standard construction unmortgageable?

BRE says mortgage lenders show a reluctance to lend on PRC homes and that individual lenders have said they support its repair scheme. It does not say that lenders refuse every non-standard house.

Can I get a mortgage on a property with Japanese knotweed?

The Property Care Association says that to meet the lender’s requirements, the management plan and its execution need to be carried out by a member of a recognised trade association. Ask the buyer’s lender what it needs.

Can cash buyers reduce offers after you agree?

A member of the Property Ombudsman’s scheme must confirm any change to its offer in writing promptly and must not reduce the price late without a valid reason explained in writing. The code covers members only.

Will a repair certificate help me sell a PRC house?

BRE says its scheme exists so that all necessary repairs can be made to the PRC house types it covers, and that individual lenders have said they support it. It covers Airey, Reema, Underdown/Winget and Wates houses only.

Sources and when we checked them

Every figure and rule on this page comes from the sources below, read on 2026-11-14. The date next to each source is the “last updated” date the publisher shows. Rules and thresholds change, so check the source before you rely on a detail.

• BRE: PRC concrete repair scheme Updated no date shown. Lender reluctance on PRC homes; the four house types and the 2016 first certificate.
• RICS: Cladding and external wall system (EWS) FAQs Updated page shows 27 October 2026. What the EWS1 form is, and the lender data.
• Property Care Association: Japanese knotweed Updated no date shown. Management plans and lender requirements.
• GOV.UK: Extending your lease or buying your freehold, plain-English explainer Updated 7 September 2026. Marriage value and leases with 80 years or fewer remaining.
• TPO: Selling your property at auction (consumer guidance) Updated June 2026. Traditional auctions tend to attract cash buyers; modern method auctions are more accessible to buyers who need a mortgage.
• TPO: Code of Practice for Residential Property Buying Companies Updated Effective from 1 June 2019; PDF on the TPO site dated March 2026. Clauses 4h and 4i on confirming and reducing offers.