Mortgages for Non-Standard Construction Homes

Last updated: 22 October 2025

What Counts as Non-Standard Construction?

In the UK, “standard construction” typically refers to houses built from brick or stone walls with a slate or tiled roof. These homes are considered safe, durable, and easy to resell. Anything that doesn’t fit this definition is usually classified as non-standard.

Common Examples of Non-Standard Construction

• Timber or Steel Frame Buildings: These were popular in certain eras. However, they may be viewed as less durable if not well maintained.

• Prefabricated or Modular Homes: Often built quickly after World War II or as affordable housing. Newer eco-modular designs are re-emerging.

  
  

• Concrete Panel Houses (PRC Types): Some were defective in the past, but many have been repaired under recognised schemes.

  
  

• Thatched Cottages or Straw Bale Homes: These are characterful but considered higher fire risk and often harder to insure.

  
  

• Properties with Flat Roofs or Unusual Coverings: These can be prone to leaks if not regularly maintained.

  
  

• Listed Buildings or Heritage Homes: Made from cob, flint, or other traditional materials, these are highly desirable but require specialist upkeep.

  
  

Because these construction types may pose durability, insurance, or resale challenges, lenders apply extra scrutiny before agreeing to a mortgage.

Why Mortgages Can Be More Difficult

Mortgages on non-standard construction homes involve more checks and sometimes stricter lending terms. Key issues include:

• Valuations and Surveys: Lenders will almost always require a detailed structural survey or report confirming the property’s condition.

  
  

• Insurance Challenges: Specialist buildings insurance is usually required, which can be more expensive.

  
  

• Deposit Requirements: Borrowers are often asked for larger deposits, sometimes 15–25%, to reduce the lender’s risk.

  
  

• Limited Lender Pool: Many mainstream lenders avoid these properties entirely, leaving specialist lenders as the main option.

  
  

• Resaleability: Lenders want assurance that the property could be sold on the open market if needed. Unusual construction can limit the buyer pool.

  
  

Intermediary Lender Options

While many mainstream lenders focus only on standard properties, there are specialist, intermediary-only lenders that may consider non-standard construction homes. Using a mortgage adviser helps match property type to a suitable lender, as each has its own criteria and often works only via brokers.

Examples of Lender Flexibility

• Some may accept a timber frame if it is modern and supported by a warranty.

  
  

• Others may allow a PRC property if it has been repaired under a recognised scheme.

  
  

• Eco-homes and modular homes may be considered if they meet building regulations and have insurance-backed warranties.

  
  

Since these lenders usually operate via brokers, using a mortgage adviser is essential to access them.

What You’ll Need to Provide

If you’re applying for a mortgage on a non-standard construction home, you’ll likely need:

• A structural or specialist survey detailing the property’s condition.

  
  

• Any warranties or guarantees if repairs or upgrades have been made (e.g. PRC repairs, new roof).

  
  

• Proof of recent improvements, such as insulation upgrades or damp-proofing.

  
  

• Evidence of stable income and good credit history to reassure lenders.

  
  

• A larger deposit to demonstrate commitment and reduce loan risk.

  
  

Options You May Have

Depending on the situation, possible routes include:

• Specialist non-standard construction mortgages via broker networks.

  
  

• Remortgaging once essential repairs or upgrades are complete.

  
  

• Product transfers with the current lender if criteria are met.

  
  

• Buy-to-let mortgages for rental properties, although with stricter terms.

  
  

• Conditional offers, where funds are released once remedial works are completed.

  
  

Regional Trends and Case Examples

The appetite for non-standard construction homes can vary by region:

• South West and Rural Areas: Thatched cottages and cob houses are more common, especially in Devon and Somerset. Lenders often rely heavily on specialist surveys for these.

  
  

• Midlands and North: PRC homes and post-war prefabs are more frequent. Some repaired under official schemes are considered mortgageable.

  
  

• Urban Areas: Modern modular or eco-build homes are increasingly seen in regeneration projects, attracting younger buyers.

  
  

Case Example

A buyer in Bristol looking at a 1960s timber-frame house may need to supply a structural survey proving the frame is sound and provide a 20% deposit. With this, some specialist lenders may offer terms similar to standard homes.

Market Trends: What’s Changed in the Last 12 Months

In 2025, several shifts have made this area more visible:

• Average rental yields have risen slightly, improving investment cases for some non-standard homes.

  
  

• More lenders now publish criteria on non-standard construction, creating clearer routes to eligibility.

  
  

• Specialist insurance products are easier to access, which helps reduce one barrier.

  
  

• Energy efficiency regulations mean more properties need upgrades before being considered mortgage-ready.

  
  

• Demand for unique rural and character homes has increased, leading to more enquiries about non-standard mortgages.

  
  

Expert Tips and Common Mistakes to Avoid

Tips

• Work with a broker experienced in non-standard construction cases.

  
  

• Arrange a full structural survey before applying.

  
  

• Carry out essential repairs early to improve mortgage eligibility.

  
  

• Keep all guarantees, certificates, and repair documents in order.

  
  

• Look at local demand and resale values, not just purchase price.

  
  

Common Mistakes

• Assuming all lenders accept non-standard construction; many do not.

  
  

• Ignoring extra costs such as specialist surveys or higher insurance.

  
  

• Expecting high Loan-to-Value mortgages; lower LTVs are more common.

  
  

• Focusing only on rate instead of lender flexibility and conditions.

  
  

• Hiding property issues, which often delays or halts applications.

  
  

Final Thoughts

Non-standard construction homes can be rewarding investments or unique places to live, but they require a more careful approach when it comes to mortgages. Options do exist, but they are usually found through specialist, broker-only channels. Success often depends on presenting the property and finances clearly.

At Manor Mortgages, we work with clients exploring non-standard homes, helping them understand the criteria and prepare strong applications. If you are considering buying or remortgaging a property of this type, we can review your case and explain your options.

FAQs

1. What counts as a non-standard construction home in the UK?

Non-standard construction usually refers to homes not built with brick or stone walls and a tiled or slate roof. This includes timber frame, steel frame, prefabricated or concrete panel houses, thatched cottages, and listed buildings made with unusual materials.

2. Can I get a mortgage on a concrete or prefab house?

It may be possible, but it often depends on the property’s condition and whether repairs or upgrades have been carried out. Some specialist lenders consider concrete or prefab homes, especially if structural certificates or repair guarantees are available.

3. Do I need a bigger deposit for a non-standard construction mortgage?

Often yes. Many lenders ask for a larger deposit, commonly 15–20% or more, to offset perceived risk. The exact requirement depends on the type of property and the lender’s criteria.

4. Will my interest rate be higher on a non-standard property?

Mortgage rates for non-standard homes may be higher than for standard construction, as fewer lenders are available and risk is considered greater. Working with a broker helps compare products and find competitive options.

5. What surveys are needed for a non-standard construction home?

Specialist surveys are usually required. For example, a structural survey for timber or steel frame homes, or a report on thatched roofs. These reports give lenders confidence that the property is safe and insurable.

6. Can I remortgage a non-standard construction property?

Remortgaging is often possible, particularly if improvements have been made since the original mortgage. Some borrowers also use product transfers with their current lender, which can be more straightforward than a new application.

7. Are non-standard construction homes harder to sell?

They can be, since fewer lenders accept them, which reduces the buyer pool. However, unique character properties such as listed cottages or modern eco homes often attract strong demand in the right markets.

Written by Ben Stephenson, CeMAP‑qualified Mortgage Broker, and reviewed by Mortgage Experts.

Manor Mortgages is FCA authorised (496907), has been in business for nearly 30 years and is highly positively reviewed (4.9 rated on Google). We have helped thousands successfully secure the right mortgage. Bristol-based mortgage brokers, but can assist nationwide.