The Cornish Unit Complete Guide [Top 8 Most Popular FAQs]

The Cornish Unit Type I is one of the most instantly recognisable non-standard construction houses in the UK. It’s important to know what type of house you’re living in, as it can affect how easy it is to mortgage and sell in the future.

So, what is a Cornish Unit house?

The Cornish Unit is a type of non-standard construction house built from pre-cast reinforced concrete (PRC). Over 30,000 of these houses were built from 1946 – 1960s in response to the post-WWII housing shortage. There are two different construction types: Type I and Type II. Both types were classified as “defective”.

Our complete guide answers the top 8 most popular questions homeowners, sellers and buyers have on Cornish Unit houses. We cover everything from how they’re built to getting a mortgage.

I also give you my personal recommendations for the best ways to sell a Cornish Unit house based on your priorities and the condition of the house.

Don't make mistakes or waste time when selling your non-standard construction home. Take our free quiz for personalised advice on the best way for you to sell:

1. What is a Cornish Unit house?

The Cornish Unit is a type of non-standard construction house built from pre-cast reinforced concrete (PRC). There are two different construction types: Cornish Unit Type I and Cornish Unit Type II.

The Cornish Unit was designed by A E Beresford and R Tonkin and manufactured by the Central Cornwall Concrete & Artificial Stone Company and Selleck Nicholls & Co.

Over 30,000 of these houses were built from 1946 – 1960s in response to the post-WWII housing shortage.

Despite the name, Cornish Unit houses were not just built in Cornwall! They can also be found across England and Wales in Kent, Somerset, and Leicestershire to name a few.

Both Type I and Type II were classified as “defective” following a review carried out by the BRE in the 1980s.

2. How are Cornish Unit houses built?

There are two distinct types of Cornish Unit houses: Cornish Unit Type I and Cornish Unit Type II. The main difference between the two types is the first-floor design.

2.1 Cornish Unit Type 1 Design

The Cornish Unit Type I is one of the most instantly recognisable non-standard construction houses in the UK.

The Cornish Unit Type I is built from precast reinforced concrete (PRC) columns on the ground floor.

Concrete panels are slotted between the column sections in pre-formed grooves. There are nine or eleven panels per storey height.

The most recognisable feature is the mansard hipped roof, which envelops the first floor.

The first floor, and roof, is a tile clad timber structure. The first-floor windows poke through tile-hung timber exterior, creating a very distinctive look.

2.2 Cornish Unit Type II Design

The external appearance of the Cornish Unit Type II design differs dramatically from the Type I variation.

Unlike the Type I design, the Cornish Unit Type II has two storeys of PRC columns with concrete panels slotted between them. The Type II system was built from 1954 – 1960s.

The Cornish Unit Type II design has four panels per storey height, compared with the nine or eleven panels of the Type I design.

The roof of the Cornish Unit Type II design does not envelop the first-floor elevation.

Cornish Units were produced as bungalows, two storey semi-detached and terraced houses, as well as flats.

3. Are Cornish Units defective?

Both types of Cornish Unit houses were designated defective under the Housing Defects Act 1984 and Part XVI of the Housing Act 1985.

This has a huge bearing on the best way for you to sell a Cornish Unit. Take this free home-selling quiz I've designed for you to help find the best way for you to sell.

The Building Research Establishment carried out a review of non-standard construction properties in the 1980s. The condition surveys revealed that certain types of non-standard construction homes suffered from structural defects. This led to them being designated as “defective” under the Housing Defects Legislation.

Generally, mortgage lenders will not lend on “defective” homes unless they are provided with a PRC Certificate. This confirms that structural repairs have been properly carried out.

PRC Certificate: A Certificate that legally proves that a PRC house has been brought up to the required construction standard recognised by banks and building societies for the purpose of mortgage lending.

4. Are Cornish Units mortgageable?

Generally, you will not be able to get a mortgage on a Cornish Unit house unless it has been repaired to the required construction standard under an approved scheme. Banks and Building Societies will want to see evidence of the repair in the form of a PRC Certificate of Structural Completion.

Even when a Cornish Unit house has been repaired, you might still struggle to get a mortgage for several reasons, including:

• Non-standard construction type. Mortgage lenders consider non-standard construction properties as higher risk. This is because they can be harder to sell and maintain.
• Repairs not up to standard. Not all repairs are equal. Extensive repairs can be made to a Cornish Unit house without meeting the approved PRC licence standard. Certain repairs will not be sufficient to satisfy mortgage lenders’ criteria.
• Changing criteria. Lender criteria changes depending on the economic landscape and housing market. Just because a Cornish Unit house is mortgageable now, it doesn’t mean the same house will be in the future and vice versa.
• Unrepaired neighbouring property. You may still struggle to obtain a mortgage from some lenders if the adjoining Cornish Unit house has not been repaired to the same standards.

If you are struggling to find a suitable lender, I recommend speaking with an experienced local mortgage broker. They will introduce you to providers who are happy to offer mortgages on repaired Cornish Units and get you the best possible deal.

5. Do Cornish Units contain asbestos?

It is safe to assume that any unmodified Cornish Unit house will contain asbestos. Cornish Unit houses were built from 1946-1960s. During this time, building materials containing asbestos were widely used. If in doubt, an asbestos survey will be able to flag the location, type, and condition of any asbestos in your Cornish Unit house.

Asbestos may be present in several places in an unmodified Cornish Unit house.

We have set out the possible locations, items, and risk level in this handy table below:

You should assume that all textured coatings contain asbestos in a Cornish Unit house until you have a full up to date survey carried out.

6. Should I buy a Cornish Unit house?

Cornish Unit houses won’t be for everyone. They can be expensive to repair, difficult to mortgage (if unrepaired) and hard to sell. However, they are almost always cheaper to buy than the equivalent standard construction house. This can make them a more affordable option for some buyers.

Cornish Units tend to be in good locations and are often built on sizeable plots. If properly repaired and maintained, they can make great homes.

However, you should consider the following factors if you’re contemplating buying a Cornish Unit house:

• PRC Certificate. Before you proceed any further, you should ask the seller to provide you with the PRC Certificate. This will confirm that the repairs were carried out to an approved standard and signed off by a structural engineer. If the house hasn’t been repaired to the approved standard, it’s unlikely you’ll be able to get a mortgage.
• Condition. What condition is the property in? You should always get a full structural survey. This will offer you guidance on the condition and flag any problems. The surveyor will also give you an estimate of the cost of any repairs. You can factor any repair costs into your offer.
• Financing. Can you finance the purchase? Unless you are a cash buyer, you will need to ensure the house has been repaired to the required standard for it to be mortgageable. Even then, only certain mortgage providers will be willing to lend on non-standard construction properties.
• Insulation. Cornish Units do not have the best insulation in their unmodified form. This can lead to higher utility costs. Ask the seller if they’ve added any insulation. If not, it may be sensible to get some building quotes for suitable insulation and adjust your offer accordingly.
• Consider resale potential. It generally takes a lot longer to sell a non-standard construction house because of the associated stigma. Some buyers can find it hard to look past the “defective” label, even when full structural repairs have been carried out. Keep this in mind if you’re planning to sell the property in the future.

Ultimately, whether you should buy a Cornish Unit house will be a decision only you can make. You should weigh up the pros and cons of that particular house, location and its future potential.

When making your decision, make sure to listen to the advice of your surveyor. If they’ve flagged any possible structural issues in their report, bring in a structural engineer for a second opinion.

It’s also vital that you get the original PRC repair certificate from the seller. This will be essential to your mortgage application success.

7. Is it hard to sell a Cornish Unit house?

Cornish Unit houses were classified as “defective” following the BRE’s review of non-standard construction properties. This makes them hard to sell as, in their unmodified form, they’re largely unmortgageable. Even when they’ve been fully repaired, buyers are put off by the stigma associated with non-standard construction homes.

The problems you might face selling a Cornish Unit house will vary depending on whether your home has been repaired.

If you're feeling overwhelmed or unsure about the best way to sell your non-standard construction home, our free quiz will help guide you in the right direction:

7.1 My Cornish Unit house has not been repaired

Some of the challenges you may face selling an unrepaired Cornish Unit house include:

1. Limited to cash buyers. An unrepaired Cornish Unit house is unmortgageable, so you will be limited to cash buyers. Cash buyers are few and far between and tend to use their strong financial position to buy properties at discounted prices.
2. Can be expensive to repair. Many prospective buyers will be put off by the cost involved in repairing the property to a mortgageable standard. Not all prospective cash buyers will be looking to carry out full repairs. Buy-to-let investors might instead choose to carry out more minor insulation repairs before letting the property. 

Suitable buyers for unrepaired Cornish Unit houses do exist…the trick is knowing where to find them!

7.2 My Cornish Unit house has been repaired

It can still be tricky to sell a Cornish Unit house even when the property has been repaired:

1. Repairs not up to standard. Unfortunately, not all repairs are equal. Extensive repairs can be made to a Cornish Unit house without meeting the approved PRC licence standard. This means that the property may not be mortgageable, and you’ll still face some of the issues associated with an unrepaired property.
2. Associated stigma. Lots of buyers will be put off a home if they find out it’s of non-standard construction. Buyers can also find it hard to look past the “defective” label, even when full structural repairs have been carried out.

Related: "Non-standard Construction: The Complete Guide [Top 9 Most Popular FAQs]".

8. What is the best way to sell a Cornish Unit house?

The best way to sell a Cornish Unit house will largely depend on whether PRC repairs have been carried out to an approved standard. Unrepaired Cornish Unit houses are best sold by auction, as you will have an audience of cash buyers and developers. If repaired, your best option is to sell with a local agent who has experience selling this property type.

8.1 Best way to sell an unmortgageable Cornish Unit house

If your Cornish Unit home is unrepaired, your best option will be to sell by auction.

Here are just some of the benefits of selling an unmortgageable Cornish Unit house by auction:

• Speed. Selling by auction is one of the fastest ways to sell a house. Sales can be agreed in as little as 6-8 weeks!
• Cash buyers. Auctions tend to attract more cash buyers and experienced developers. They won’t be put off by a non-standard construction build. Investors and developers will be at auctions looking for opportunities to add value and a solid return on investment.
• Success rate. Auctions have a higher success rate of 78% (compared with estate agents at just 51%).
• Experience. Auctioneers tend to have more experience dealing with non-standard construction houses than many estate agents. Problem properties, such as “defective” homes, tend to be better suited to auction.
• Certainty. You’ll have a much higher chance of achieving a sale. Less than 1% of sales agreed by traditional auction fall through. By comparison, 31% of all house sales fall through at least once before completion if sold on the open market. This figure tends to be a lot higher when selling a non-standard construction house.

If your property has been repaired, you have more suitable options when it comes to selling…

8.2 Best way to sell a repaired Cornish Unit house

If your Cornish Unit house has been repaired to the approved PRC standard, you have two options when it comes to selling.

The best one for you will depend on what you prioritise the most: time or money.

Best price possible

If you want to achieve the best price possible, then selling with a good, local estate agent is the best option for you.

Try to find an agent who has a good understanding of Cornish Unit houses and how they perform in the local market. The last thing you want is an uninformed agent putting off potential buyers.

Just be prepared that it might take a long time to sell your Cornish Unit house this way.

According to a 2022 study by Zoopla, it takes around 25 weeks on average to sell a house. Remember that this is an average. Non-standard construction properties, like Cornish Unit houses, tend to take even longer to sell!

If you don’t have the luxury of time, then selling your house by auction might be a better option for you…

Faster and more certain sale

If you want to achieve a faster and more certain sale, then selling by auction is the best option for you. Auctions offer a great balance between speed and price.

Selling by auction is also a good backup plan if you aren’t having much luck selling with an estate agent.

Take this free quiz to see if auction is a good fit for you. If it is, I can connect you with my #1 Leading Auction House in your area. You can get a free auction appraisal and have all your auction questions answered (for free) in the next 24 hours.

You can also read more about the benefits of selling by auction in my guide, “17 Benefits Of Selling Your House By Auction [What Customers Say]”.