Non-Standard Construction: Buyer & Seller Guide (2026)
- What counts as non-standard construction?
- The main types you will meet in Scotland
- Why non-standard construction matters: mortgage, value, insurance
- Mortgages: the single biggest constraint
- Valuation and the Home Report
- Buildings insurance
- How to sell a non-standard construction home
- What it costs to sell
- How long it takes
- Who this affects most
- Alternatives to selling
- Risks and mistakes to avoid
- The bottom line
What counts as non-standard construction?
Most houses in Scotland are 'standard construction': masonry walls (brick or stone, often cavity) carrying the load, topped with a pitched, tiled or slated roof. Anything that departs from that in a way lenders and surveyors treat as higher-risk is labelled non-standard construction. The label is not a judgement on how nice the home is - plenty of non-standard houses are warm, spacious and structurally sound - it is a shorthand for 'a mainstream lender will want to look more closely before lending on it'.
This guide sits alongside two more specific ones: if you first need to work out what you are dealing with, read how to tell if a house is non-standard construction; if your home is a post-war steel-framed type, read what BISF house construction is. Here we focus on what non-standard construction actually means for money - the mortgage, the valuation and the insurance - whether you are buying or selling.
The main types you will meet in Scotland
Non-standard is an umbrella covering many build systems. The most common ones a Scottish buyer or seller runs into are below, with the practical issue each one tends to raise.
| Construction type | What it is | Typical concern |
|---|---|---|
| Steel frame (incl. BISF) | Steel skeleton clad in render, brick or panels; ~35,000 BISF built 1944-1950 | Frame corrosion at the base; thinner lender pool |
| PRC (pre-cast reinforced concrete) | Concrete panels/columns - Airey, Cornish, Wates, Woolaway, Orlit | Many 'designated defective'; often needs a licensed repair scheme |
| Timber frame | Load-bearing timber structure behind an outer skin | Modern is fine; older or damaged frames need a survey |
| System / prefab | Factory-built panel or 'no-fines' concrete (e.g. Wimpey No-Fines, Laing Easiform) | Case-by-case; some types lend easily, others do not |
| Single-skin, cob, thatch | Solid single-leaf walls, earth walls, thatched roofs | Insurance cost and damp/repair, especially rural and period homes |
Two of these carry a specific legal history worth knowing. Certain PRC types - Airey houses among them - were designated 'defective' under the Housing Defects legislation and later the Housing Act 1985 because of concerns about the reinforcement corroding inside the concrete. A designated-defective home that has not been repaired to an approved standard is very hard to mortgage. Once it is repaired under a licensed scheme and certified, mortgageability usually returns.
Why non-standard construction matters: mortgage, value, insurance
For most buyers and sellers, the construction type only ever bites in three places: whether a lender will advance a mortgage, what a surveyor puts in the Home Report, and what an insurer will charge. Get those three right and a non-standard home behaves much like any other. Get them wrong and the sale stalls.
Mortgages: the single biggest constraint
This is the decisive factor. Mainstream lenders assess a property on durability and resale risk - they need to know they could sell it on if they ever repossessed. A construction type they see as short-lived or hard to resell narrows their appetite. In practice that means fewer lenders will consider the home, and those that do often apply stricter terms.
As of 2026, a mortgageable non-standard home (sound, or repaired and certified) can typically be financed through specialist and some high-street lenders, though frequently at a lower maximum loan-to-value - commonly in the region of 75-85% rather than the 90-95% available on standard homes. Lenders will usually require the Home Report Single Survey, and may ask for an additional structural engineer's report or a valid repair certificate before they commit. An un-repaired designated-defective type may attract no mainstream lender at all, leaving cash buyers as the realistic market.
If a lender has already declined your home, our guide on what to do when your home is unmortgageable walks through the routes back to a sale. Cladding-affected flats sit in a related but separate category, covered in can you get a mortgage on a flat with cladding.
Valuation and the Home Report
In Scotland every marketed home needs a Home Report, and its Single Survey is where construction issues surface. The surveyor gives each element a condition rating of 1 (no repair needed), 2 (repairs or maintenance needed) or 3 (urgent repair or replacement, or further investigation needed). A category 3 against the structure, or a note recommending a specialist report, is a red flag to lenders and will usually knock the valuation and the buyer pool.
Construction type also feeds the surveyor's market value figure directly. Because demand is thinner, a non-standard home commonly values below an equivalent standard house nearby. That gap is not a flaw in the survey - it reflects the smaller number of buyers who can actually complete. Understanding that early helps you price realistically and avoid a sale that drags.
Buildings insurance
Insurance is the quieter of the three issues but still real. Some insurers load the premium for steel-framed, concrete or thatched construction, and a minority decline certain types altogether, so cover may need a specialist broker. Buyers should get an insurance quote before committing, because a mortgage offer is normally conditional on buildings cover being in place from the date of entry. It is rarely a deal-breaker, but it is a cost to budget for.
How to sell a non-standard construction home
Because so many buyers rely on a mainstream mortgage, a non-standard home can sit unsold on the open market while mortgage-dependent buyers fall away at the survey stage. There are three realistic routes, and the right one depends on how mortgageable your specific home is and how quickly you need to move.
| Route | Typical timeline | Price achieved | Best when |
|---|---|---|---|
| Open market (estate agent) | 2-6 months, sometimes longer | Full market value if a mortgageable buyer is found | The home is sound or certified and you are not in a hurry |
| Cash-buying company | 7-14 days | ~75-85% of market value | You need speed and certainty and will trade price for it |
| Auction | ~28 days to completion | Competitive - cash investors bid against each other | You want speed AND to keep the price honest via competition |
Auction tends to suit these homes particularly well because it reaches the exact audience that wants them: cash investors and developers who buy non-standard property deliberately, are unfazed by the mortgage constraint, and compete on price. At Scotland Property Auction that audience is a database of around 11,000 registered buyers. A successful bid is secured with a non-refundable deposit - 10% under our SaleLock Guarantee - so the sale does not evaporate at survey stage the way a mortgage-dependent open-market sale can. See how selling at auction works for the full process, and if yours is a steel-framed home read selling a BISF property at auction.
What it costs to sell
The main Scotland-specific cost is the Home Report, which in 2026 typically runs around £400-£800 including VAT depending on the property's size and value. On the open market you would add estate-agent commission (commonly about 1-1.5% plus VAT) and your solicitor's conveyancing fee. A reputable auction route is usually no sale, no fee - you pay nothing if it does not sell - which removes the risk of paying an agent for months of marketing that never completes.
How long it takes
On the open market, a mortgageable non-standard home might sell in two to six months, and an un-repaired defective type can take far longer or not sell at all to a mortgage buyer. A cash-buying company can complete in one to two weeks. An auction sale typically completes within about 28 days of the hammer, because the buyer is committed and the timetable is fixed.
Who this affects most
Owners of PRC, Airey, Cornish, BISF and other post-war system-built homes feel this most sharply, as do buyers hoping to snap up a bargain that then proves unmortgageable. Executors selling an inherited non-standard house, and landlords offloading an ageing steel-framed let, are also common. In every case the deciding question is the same: can a mainstream lender advance a mortgage on it, or not?
Alternatives to selling
Selling is not the only option. If the barrier is a defective PRC type, repairing it under a licensed scheme and obtaining a certificate can restore mortgageability and lift the value - though repair costs are substantial and only pay off on some homes. Retaining the property as a cash-let, or refinancing through a specialist lender rather than selling, can also make sense. Weigh the repair cost against the value uplift before committing.
Risks and mistakes to avoid
The commonest mistake is marketing a non-standard home to mortgage-dependent buyers and losing weeks to sales that collapse at survey. The second is over-pricing against standard homes nearby and then chasing the price down. The third, for buyers, is failing to check mortgageability and insurance before committing. And for sellers, non-disclosure is a real risk: the Home Report Property Questionnaire asks about the property, and misrepresenting a known structural issue can expose you to a claim. Honesty, an early survey and the right sales route are the antidotes.
Key takeaways
- Non-standard construction covers steel, concrete (PRC), timber, prefab and period build types.
- Mortgage availability is the key constraint - fewer lenders and usually a lower maximum LTV (often ~75-85% in 2026).
- The Home Report Single Survey is where construction issues surface and feed the valuation.
- Insurance can cost more or need a specialist broker - buyers should quote before committing.
- A licensed repair and certificate can restore mortgageability on defective PRC types.
- Auction reaches cash investors who want these homes, keeping the price competitive and the sale certain.
The bottom line
Non-standard construction is a mortgage-and-market label, not a verdict on the house. Once you know whether a mainstream lender will lend on your specific home, everything else - the valuation, the insurance, the right way to sell - follows from that single fact. If mortgageability is limited and you want a fast, certain sale at a competitive price, a cash-buyer auction is usually the strongest route. Get a free 60-second valuation to see where your home stands.
Founder & Director of Scotland Property Auction. Julie has spent over a decade helping Scottish homeowners, landlords and executors sell property quickly at auction — covering Home Reports, missives, repossession and the modern method of auction.
More about Julie →✔ Last reviewed June 2026 by Julie McAndrews. We keep our guides current with Scottish property law and market conditions.