Buying, renovating or developing a property that falls outside traditional construction methods can feel complex, particularly when it comes to securing finance. Non-standard construction properties often present additional challenges for mainstream lenders, but specialist finance options, including development finance, can provide a practical and flexible solution.
In this guide, we’ll explain what non-standard construction finance is, which property types are affected, and what you can do to improve your chances of approval.
What is non-standard construction?
In the UK, a property is typically classed as non-standard construction if it’s not built using traditional brick or stone walls with a tiled or slate roof. This doesn’t mean the property is unsafe or poorly built, just that it falls outside lenders’ usual comfort zones.
Common examples include:
- Timber frame properties
- Prefabricated (prefab) homes
- Properties affected by mundic
- Grade II listed and period properties
Each comes with its own considerations when applying for finance.
Timber frame properties
Timber frame homes are far more common than many buyers realise, particularly in Scotland and newer UK developments. Modern timber frame properties are built to strict building regulations and can be just as durable and energy-efficient as traditional homes.
Finance considerations:
- Modern timber frame (post-2000) is generally well accepted by mainstream lenders
- Older timber frame properties may require additional surveys
- Fire resistance and maintenance history can influence lender decisions
How development finance can help
Development finance can support new-build or refurbishment timber frame projects by funding construction costs in stages, aligned to progress on site. This can be particularly useful where traditional mortgages are unavailable until completion.
Tip: Providing evidence of compliance with modern building standards can significantly help your application.
Prefabricated (prefab) homes
Prefab homes were often built after World War II to address housing shortages. Some types, such as Airey, Cornish or Unity houses, can be more challenging to finance, particularly if they haven’t been repaired under approved schemes.
Finance considerations:
- Some prefab types are mortgageable, others are not
- Lenders will usually want confirmation of approved repairs or certification
- Structural condition is critical
How development finance can help:
Development finance can be used to acquire and refurbish prefab properties, fund approved repair schemes, or convert them into mortgageable assets, unlocking value that mainstream lenders may initially overlook.
Tip: If repairs have been carried out, keep all documentation, it can make a major difference.
Mundic properties
Mundic refers to properties in parts of Cornwall and Devon where concrete was made using mine waste. Over time, this can cause structural deterioration.
Properties are typically classified following a mundic survey (Classes A1 to A3).
Finance considerations:
- Class A1 properties are usually acceptable to most lenders
- Class A2 or A3 properties are much harder to finance
- Specialist lenders may still consider some cases
How development finance can help
Specialist development finance can assist with acquisition, testing, and remedial works, enabling borrowers to improve the property’s classification and create a viable exit through sale or refinance.
Tip: Always commission a mundic report early, it can save time and unexpected costs later.
Grade II listed and period properties
Grade II listed buildings and period homes are prized for their character and history, but they come with unique responsibilities.
Finance considerations:
- Lenders assess condition, maintenance, and alteration restrictions
- Specialist materials or construction methods may affect valuation
- Insurance and repair costs are closely scrutinised
How development finance can help
Development finance provided by specialist lenders can support sensitive refurbishments, restorations or conversions, offering flexibility around property type, age and construction, particularly where traditional mortgage criteria fall short.
Tip: Demonstrating a clear plan for ongoing maintenance reassures lenders and valuers alike.
How to improve your chances of securing finance
If you’re buying or remortgaging a non-standard construction property, preparation is key:
- Use a broker experienced in non-standard construction finance
- Expect more detailed surveys and valuations
- Have a strong deposit where possible
- Keep documentation organised (certificates, repairs, surveys)
Specialist lenders exist precisely for these scenarios, and criteria has continued to evolve in recent years, making more options available than many buyers expect.
Why development finance is often the right solution
For non-standard construction projects, development finance can offer several advantages:
- Funding for purchase, refurbishment or full redevelopment
- Flexible criteria tailored to complex property types
- Stage releases aligned to build progress
- Viable routes to exit via sale or refinance once works are complete
Your client’s development finance solutions are designed to support projects that fall outside conventional lending criteria, helping borrowers move forward where high-street lenders may say no.
How a development finance calculator can help
Before committing to any development project, understanding the numbers is essential. A development finance calculator can provide a useful early indication of borrowing potential, estimated costs and funding structure.
Used correctly, a calculator can help borrowers:
- Estimate how much they may be able to borrow
- Understand likely loan-to-cost or loan-to-GDV levels
- Sense-check whether a project is financially viable
- Prepare more effectively before speaking to a lender or broker
While a calculator won’t replace a full assessment, it’s a valuable planning tool that helps set realistic expectations and encourages better-informed conversations about development finance.
Final thoughts
Non-standard construction doesn’t mean non-mortgageable. Whether you’re considering a timber frame home, a prefab property, a mundic-affected house, or a Grade II listed period gem, the right guidance can open doors that might initially seem closed.
With expert advice and the right lender, financing your unique property is entirely possible.