Non-standard construction mortgages in the UK: lenders and how to get one
Securing a mortgage for a home built with materials other than brick and tile can seem challenging, especially if you have already been declined due to the construction type. However, obtaining a mortgage for a non-standard construction property is often possible. While the process is more complex than for standard homes, it is rarely impossible.
The key factor is often the lender. Many high-street banks follow strict rules for non-standard construction, while specialist lenders review these properties individually. Working with a broker who understands lender criteria can save time and help turn a likely decline into an approved application.
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Can you get a mortgage on a non-standard construction property?
Yes, in most cases you can, but lender options are more limited, and criteria are stricter than for standard brick-and-tile homes. Whether buying or remortgaging, it is important to match the property with a lender experienced in that construction type.
Lenders are cautious because some non-standard construction methods are considered less durable, harder to insure, or more difficult to resell, which affects their value as security. While this does not prevent you from getting a mortgage, it usually requires a more thorough assessment, a larger deposit, and often a specialist lender instead of a high-street bank. A broker with access to specialist lenders can be especially helpful.
What is a non-standard construction property?
In lending terms, a “standard construction” property has walls of brick or stone and a roof of tile or slate. A non-standard construction property is essentially anything built differently. That covers a wide range of homes, from timber and steel frames to concrete-based construction, prefabricated panels, thatched or flat roofs, and high-rise flats.
Lenders evaluate these homes carefully because construction methods impact durability, maintenance, insurance, and resale value. The term “non-standard” is broad and does not necessarily indicate high risk. For example, lenders view a well-maintained timber-frame house and a defective concrete property very differently.
Types of non-standard construction
Non-standard construction covers many building methods, and each carries its own considerations for a mortgage. The table below gives a general guide. Individual lender criteria vary, and the condition of the specific property matters as much as the category it falls into.
| Construction type | What it is | Typical mortgage difficulty |
|---|---|---|
| Timber frame | A load-bearing timber structure, often behind a brick or rendered outer skin | Moderate |
| Steel frame | A steel structural frame, common in some post-war and ex-council homes | Moderate to higher |
| Concrete / PRC | Pre-reinforced concrete; some types were later designated defective | Higher (often requires a completed repair scheme) |
| Wimpey no-fines | A form of in-situ “no-fines” concrete; widely built and generally lendable | Moderate |
| Prefab / precast | Factory-made panels assembled on site | Higher |
| Thatched roof | A traditional thatched roof, usually an insurance rather than structural concern | Moderate |
| Flat roof | Properties with a large proportion of flat roof | Moderate |
| High-rise flats | Flats above a certain number of storeys, with lender limits varying | Moderate |
| Ex-council / PRC designated | Former local-authority homes, some designated under the Housing Defects Act 1984 | Higher |
If your property is a steel-frame or timber-frame home, options are often wider than owners expect. For concrete or PRC properties, the outcome usually depends on whether an approved repair scheme has been completed and can be evidenced. We can help you work out where your property is likely to sit before you apply.
Why is it harder to get a mortgage on non-standard construction?
The extra caution comes down to risk, not prejudice. Lenders are lending against the property as much as against your income, so anything that affects the building’s long-term value or saleability affects their decision.
The main reasons a non-standard property is treated more carefully include:
Durability
Some construction methods have a shorter expected lifespan or a history of structural issues, which makes lenders more conservative.
Resale risk
If a home is harder for the next buyer to mortgage, it can be harder to sell, and that affects the lender’s security.
Insurance. Certain types, such as thatched roofs or some concrete builds, can be more expensive or more complex to insure.
Insurance
Certain types, such as thatched roofs or some concrete builds, can be more expensive or more complex to insure.
Designated defective status
Some precast concrete homes were designated defective under the Housing Defects Act 1984, and lenders will want to see that appropriate repairs have been carried out.
The practical effect is usually a narrower set of lenders, a larger deposit, and closer scrutiny of the property, rather than an outright barrier to borrowing.
Which lenders offer non-standard construction mortgages?
There is no single list, because lenders take very different positions depending on the construction type. Broadly, the market splits into two groups.
High-street lenders typically follow strict criteria and may decline or restrict certain construction types. Some may accept common non-standard types, such as timber or steel frame, if the property is in good condition and the deposit is substantial. Others have policies that exclude all non-standard construction.
Specialist lenders tend to be more flexible. They typically use manual underwriting, which means a real person assesses the property and your circumstances rather than an automated rule declining the case outright. They are more likely to consider concrete, prefab and previously declined properties, usually in exchange for a larger deposit or a slightly higher rate.
A broker’s value here is knowing, from experience, which lenders currently consider which construction types, so your application goes to a lender likely to say yes rather than one likely to decline.
Not sure which lenders would consider your property?
We can check your options across specialist lenders before you make a full application.
How do lenders assess a non-standard construction property?
Assessment focuses on the property. In addition to standard income and affordability checks, the lender will arrange a valuation or survey that emphasises construction. Additional evidence may be required depending on the property type.
For most non-standard homes, the surveyor verifies the construction method, condition, and suitability as security. For precast concrete (PRC) properties, lenders typically require a PRC certificate confirming repairs to an approved scheme and a structural report. The property’s status, repair history, and overall condition all influence the decision.
Two homes of the same construction type may receive different outcomes based on maintenance and documentation. Lenders are reassured by clear evidence, such as a construction-focused survey, certificates for completed repairs, and proof of good upkeep. If evidence is lacking, the lender may request more information or decline the application. Knowing lender requirements in advance is beneficial.
What deposit do you need for a non-standard construction mortgage?
Deposit requirements are usually higher than for a standard property. As a general guide, many lenders look for at least 10% to 25%, and sometimes more, depending on the construction type and the lender.
As a rule of thumb, the more complex or higher-risk the construction, the larger the deposit a lender is likely to want. A timber-frame home in good condition may need only slightly more than a standard property, while a defective-designated concrete house is likely to sit at the higher end of the range. The exact figure will depend on the lender’s criteria and your wider circumstances.
Non-standard construction mortgage rates
Rates on non-standard construction mortgages are typically a little higher than the lowest high-street deals, reflecting the additional risk and the more specialist nature of the lending. How much higher depends on the construction type, the size of your deposit, and the individual lender.
Because the market is more specialist, the difference between a competitive deal and an expensive one can be significant, and the lowest headline rate is not always the one you’ll qualify for. The right deal is the one a suitable lender will actually offer on your property, not simply the lowest rate advertised. A broker can compare the options that genuinely fit your construction type and circumstances.
How to get a non-standard construction mortgage
Getting a mortgage on a non-standard property is more straightforward when you approach it in the right order. A typical route looks like this:
- Identify the construction type. Confirm exactly how the property is built, since this drives everything that follows. A surveyor or the seller’s information can help.
- Get advice from a specialist broker. An adviser can tell you early which lenders are likely to consider your property, so you don’t waste an application on a lender that will decline it.
- Arrange the right survey. A construction-focused survey (and, for PRC, evidence of any repair scheme) gives lenders the reassurance they need.
- Get an Agreement in Principle. This gives you an early indication of how much a suitable lender may be willing to lend, subject to a full application.
- Apply to a suitable lender. With the property type confirmed and the right lender identified, you submit a full application supported by the necessary documents.
Taking advice before you apply is particularly valuable with non-standard construction, because a single well-matched application is far better than several speculative ones.
We would be happy to clarify your mortgage options.
What documents and checks do you need?
Alongside the standard mortgage paperwork, a non-standard construction application usually calls for extra evidence about the property. Being prepared helps the process run smoothly. You’ll typically need:
- proof of identity and address
- proof of income (payslips and P60, or accounts and SA302s if you’re self-employed)
- evidence of your deposit and its source
- a survey or construction report confirming the building type and condition
- a PRC certificate, where the property is precast reinforced concrete
- documentation of any repairs already carried out, where relevant
The exact requirements depend on the lender and the construction type. Having the property documents ready in advance can make a real difference to how quickly an application progresses.
Common issues and how to overcome them
Most obstacles with non-standard construction have a practical route around them. A few of the situations we see most often:
PRC or designated-defective concrete.
The usual solution is evidence of a completed repair scheme to an approved standard, together with the relevant certificate, which opens up more lenders.
Ex-council property.
These can be very mortgageable, but they often suit a specialist lender who is comfortable with the specific construction type.
A previous decline.
A decline by one lender does not mean the property is unmortgageable. It usually means it was sent to the wrong lender. A broker can identify one better suited to the construction type.
Insurance difficulties.
Some non-standard homes need specialist buildings insurance. Arranging this early can prevent delays later in the process.
In practice, most of these issues are about matching the property to the right lender and presenting the right evidence, rather than a fundamental barrier to borrowing.
Example scenarios
While each case is unique, the following examples illustrate how these applications typically work in practice.
Steel-frame ex-council home, previously declined
A buyer’s offer on a well-maintained steel-frame former council house was rejected by their bank, which did not lend on that construction type. When the application was submitted to a specialist lender familiar with steel-frame properties, it proceeded with a slightly larger deposit and a manual property assessment. The initial decline was due to lender policy, not the property’s condition.
PRC house with completed repair scheme
A couple sought to purchase a precast reinforced concrete (PRC) property repaired under an approved scheme. The essential factor was documentation: the PRC certificate and structural reports confirmed the repairs, reassuring the lender that the property was acceptable security. With proper paperwork and a suitable specialist lender, the mortgage was approved. Without this evidence, securing funding would have been much more difficult.
The common thread in both is straightforward: the outcome improved once the property was matched to a lender that understood the construction type and the right evidence was in place.
Buy-to-let on non-standard construction
A buy-to-let mortgage on a non-standard construction property is possible, but the choice of lenders is narrower still, since the property needs to satisfy both non-standard construction criteria and buy-to-let criteria. A larger deposit is usually required. If you’re considering this, speak to an adviser about the specialist options available. You can also read more about our buy-to-let mortgage service.
Why use Smart City Mortgages for a non-standard construction mortgage
Non-standard construction is precisely where a broker adds value. We work with specialist lenders who assess these properties individually and know which lenders currently accept specific construction types.
We can direct your application to a lender likely to approve it, help you gather the necessary property evidence, and save you time and stress. As an FCA-authorised broker, we’ll explain your options clearly and support you from your initial enquiry to completion.
Frequently Asked Questions
Yes, in most cases. The choice of lenders is narrower and the criteria stricter than for a standard home, and a specialist lender is often the best route. Advice before you apply helps match your property to a suitable lender.
Any property that isn’t built with brick or stone walls and a tile or slate roof. That includes timber and steel frame, concrete and PRC, prefab, thatched or flat roofs, and high-rise flats, among others.
Some high-street lenders consider the more common types, such as timber or steel frame, while specialist lenders cover a wider range using manual underwriting. The right lender depends on the specific construction type and the property’s condition.
Some do, for certain construction types and in good condition, but many apply cautious rules or decline outside standard construction. Where a high-street lender won’t help, a specialist lender often will.
Usually more than for a standard property, often in the region of 15% to 25% or more, depending on the construction type and the lender.
Typically a little higher than the lowest high-street deals, reflecting the additional risk. The exact rate depends on the construction type, your deposit, and the lender.
Often yes, particularly where an approved repair scheme has been completed and can be evidenced with a PRC certificate. Specialist lenders are usually more comfortable with these properties.
Frequently yes. These are among the more widely accepted non-standard types, and some high-street as well as specialist lenders may consider them, subject to condition and deposit.
Yes, remortgaging is usually possible using the same specialist lenders. If your current deal is ending, it’s worth reviewing your options early. You can compare options on our remortgage deals page.
Ready to get a non-standard construction mortgage?
If you’re buying or remortgaging a non-standard construction property, the right advice makes all the difference. We’ll help you understand your options, match your property to suitable lenders, and move forward with confidence.
