What Is Considered Non-Standard Construction?

Understanding Which Properties Are Classed as Non-Standard Construction

Learn what is considered non-standard construction, which property types are commonly affected and why construction methods can influence mortgage availability, insurance and buyer demand.

What Makes a Property Non-Standard Construction?

A non-standard construction property is a home built using materials or construction methods that differ from traditional brick-and-block construction.

While there is no single legal definition, mortgage lenders, insurers and surveyors often use the term to describe properties built using alternative construction techniques or materials that may require additional assessment.

Many non-standard construction homes were built during the twentieth century, particularly after the Second World War, when rapid housebuilding programmes were introduced to address housing shortages across the UK.

Although many of these properties remain perfectly habitable and continue to be bought and sold successfully, some construction types can be viewed differently by mortgage lenders, insurers and surveyors.

If you’re considering selling, you can also learn more in our guide to Sell a Non-Standard Construction Property Fast.

Common Types of Non-Standard Construction Property

Concrete and PRC Houses

Many post-war homes were constructed using precast reinforced concrete (PRC) systems. Some PRC properties remain mortgageable, while others may require specialist assessment depending on their construction type and repair history.

Timber-Framed Houses

Timber-framed construction is widely used in modern housing, although some older timber-framed properties can attract additional scrutiny from lenders and surveyors.

BISF Houses

British Iron and Steel Federation (BISF) houses use a steel frame construction method and are one of the best-known examples of non-standard housing.

Airey Houses

Airey houses were built using prefabricated concrete components and are commonly recognised as a non-standard construction type.

Cornish Unit Properties

Cornish Unit homes were built using reinforced concrete construction systems and may be assessed differently by lenders depending on their condition and any remedial works completed.

Wimpey No-Fines Houses

These properties were constructed using concrete without fine aggregate. While many remain mortgageable, lenders may still consider the construction type during valuation and underwriting.

Are All Non-Standard Construction Homes Difficult to Mortgage?

No. Many non-standard construction properties are readily mortgageable and continue to attract strong buyer demand.

However, mortgage availability often depends on factors such as:

  • The construction type
  • Property condition
  • Repair history
  • Structural survey findings
  • Individual lender criteria

Some construction methods are widely accepted by lenders, while others may require specialist lending solutions.

COMMON LENDER
CONCERNS

Construction durability
Long-term maintenance
Future resale value
Structural condition
Insurance availability

Even where a property is well maintained, lenders may still assess non-standard construction differently from traditional brick-built homes.

FACTORS THAT CAN IMPROVE BUYER CONFIDENCE

Positive survey results
Good repair history
Available mortgage products
Suitable insurance cover
Clear property documentation

Many buyers are primarily looking for reassurance that the property is well maintained and that any construction-related considerations are understood.

Not all non-standard construction properties are viewed in the same way. Some construction methods are widely accepted by lenders and insurers, while others may attract additional scrutiny. As a result, two seemingly similar properties can experience very different levels of buyer demand and mortgage availability.

Example: Why Similar Properties Can Be Viewed Differently

Imagine two similar houses in the same area.

Property A is a traditional brick-built house with no unusual construction features.

Property B is a BISF steel-framed house of a similar size and condition.

Although the two properties may appear similar, mortgage lenders, insurers and some buyers may assess them differently because of the construction method used.

Property A may appeal to a wider range of mortgage-backed buyers, while Property B may attract additional questions regarding construction type, insurance and future resale considerations.

This example demonstrates why construction type can influence buyer demand and mortgage availability, even where properties are otherwise comparable.

Related Non-Standard Construction Guides

Sell a Non-Standard Construction Property Fast

Auction can provide an alternative route to sale by exposing your property to investors, developers and cash buyers who are experienced in purchasing non-standard construction homes.
Read more: Sell a Non-Standard Construction Property Fast

Can You Get a Mortgage on a Non-Standard Construction House?

Learn how lenders assess non-standard construction properties and why mortgage availability can vary.
Read more: Can You Get a Mortgage on a Non-Standard Construction House?

Does Non-Standard Construction Affect Property Value?

Understand how construction type can influence value, buyer demand and achievable sale price.
Read more: Does Non-Standard Construction Affect Property Value?

Are Non-Standard Construction Houses Harder to Insure?

Some non-standard construction properties can be more expensive to insure or may require specialist insurance providers.
Read more: Are Non-Standard Construction Houses Harder to Insure?

Selling a Non-Standard Construction Property

For many owners, auction is one of the fastest and most reliable ways to sell a non-standard construction property.

Auction can provide access to investors, developers and cash buyers who are already familiar with these types of properties and understand the opportunities they can present.

Why auction can work well:

  • Buyers are often cash-funded
  • Reduced risk of fall-throughs
  • Faster completion times
  • Sell in current condition
  • Wider investor exposure

Auction can be particularly effective for difficult-to-finance properties where traditional buyers struggle to proceed.

Read more: Sell a Non-Standard Construction Property Fast

Sell a non-standard construction property through auction, featuring cash buyers, reduced mortgage concerns, and a fast sale process.

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Why Use Us?

We help homeowners understand how construction type can affect mortgage availability, buyer demand and the sale process when dealing with non-standard construction property.

Construction-related concerns can sometimes create uncertainty, particularly where buyers, lenders and insurers assess a property differently from a traditional brick-built home. Understanding these factors can help you make more informed decisions about your options.

Backed by more than 20 years of experience in estate agency and property sales, we understand the challenges many homeowners face when selling non-standard construction homes. Working alongside experienced auction professionals and established UK auction partners, we provide practical guidance, trusted information and access to specialist property expertise.

Whether you’re researching construction types, considering selling or simply looking to understand your options, we’re here to help without any obligation or pressure.

If you decide selling could be the right next step, we can also provide a free, no-obligation auction valuation and explain the options available for your property and circumstances.

Frequently Asked Questions About Non-Standard Construction

Non-standard construction refers to properties built using materials or methods that differ from traditional brick-and-block construction. Common examples include PRC houses, BISF steel-framed homes, Airey houses, Cornish Unit properties, timber-framed houses and other system-built housing types.

No. Many non-standard construction properties remain mortgageable and continue to attract strong buyer demand. Mortgage availability often depends on the specific construction type, property condition, repair history and individual lender criteria.

Examples of non-standard construction include concrete and PRC houses, BISF steel-framed properties, Airey houses, Cornish Unit homes, Wimpey No-Fines houses, timber-framed properties and various prefabricated or system-built housing types.

In some cases, yes. Mortgage availability, buyer demand and lender attitudes can all influence how a non-standard construction property is valued. The impact varies depending on the construction type, condition of the property and local market demand.

Yes. Many non-standard construction properties can be insured, although some may require specialist insurers or attract higher premiums. Insurance availability often depends on the construction type, property condition and claims history.

Yes. Non-standard construction properties are bought and sold every day across the UK. While some buyers may be cautious due to mortgage or insurance considerations, many investors, landlords, developers and cash buyers actively purchase these types of homes.

Auction can be an effective option where mortgage restrictions reduce the number of traditional buyers. It provides access to investors, developers and cash buyers who are often familiar with non-standard construction properties and can proceed without relying on mainstream mortgage finance.

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