Properties that have a single layer of brick for a wall, or the entire building, are known as single brick, or single skin, construction. They’re different from buildings made with a cavity wall which features 2 layers of masonry, each being usually around 4 inches thick. Buildings constructed in a single layer of brick - also known as a solid wall - are classed by mortgage lenders as non-standard construction, which limits the options for getting a mortgage. Fortunately, it’s possible to find a mortgage for all kinds of property types, including single brick construction - even in the situation where you have a poor credit rating or have had a mortgage application rejected previously. If you’re interested in purchasing and getting a mortgage on a single brick construction property, this guide should help.

What Is a Single Brick Construction Property?

Buildings constructed with a single layer of brick for the external walls were popular in Victorian times. This was especially the case with smaller Victorian terraced houses. It’s not uncommon for the end of terrace houses to have the side wall built of single skin brickwork. This could be either because they were built cheaply, or because of bomb damage during the war - where a mid-terrace house suddenly became an end terrace. If the original chimney breast or internal walls that used to support these thin walls have been removed, it can mean the single brick layer is vulnerable to collapse.

Single skin wall construction is atype of construction that falls under the non-standard property umbrella, which could restrict your choice of the mortgage lender. Getting a mortgage on a non-standard construction is complicated as the mortgage lender needs to understand the risks before considering any mortgage application.

Can You Get a Mortgage on a Single Skin Property?

Yes, it is possible to get a mortgage on a single skin property, but it will not be as easy as with a more conventionally built brick building constructed in line with modern standards. Lenders have become more risk averse about single brick construction mortgages. They view this type of building as being of non-standard construction. This means that you may have difficulties using a high street mortgage provider and may need to find a specialist lender or building society. Specialist lenders and buildings societies typically come with more flexible criteria but higher rates. It makes sense to work with a broker with whole of market access to the mortgage lending market like John Charcol to help guide you to the right mortgage provider.

You may run into further problems finding a mortgage if the property you have in mind has single brick construction on several of the external walls and has 2 floors. It’s also possible you might run into difficulties if the building you’d like to buy only has one external wall but has 2 storeys.

If you find yourself in this situation, the value of the property you’re looking to buy is potentially going to be lower. This is because of the relative difficulty a buyer will have finding a suitable lender for the property. Some lenders will require that you get a structural engineer’s survey report and agree to add an additional layer to add stability to the wall. Adding another layer of brick will help with insulation and mitigate the risk of damp. The new brick layer could be a new inner leaf, or a second external layer made in lightweight blockwork with a damp proofing course in between the layers.

Why Is It Difficult to Get a Mortgage on a Single Skin Building?

There are 3 main problems associated with a single skin building. First, is the potential structural weakness of an external wall built with a single layer of brick. Second, is the lack of thermal insulation, which is likely to mean the rooms in the building do not retain heat in winter and stay cool in summer. Third, the building may have issues with condensation and dampness and have poor sound insulation.

These 3 issues are of significant concern to mortgage providers, as they’ll want to be sure that the building can be sold in the event of repossession. Lenders fear that it may take a long time to find a buyer, or they may be required to reduce the value to attract a buyer.

Mortgage providers, therefore, place a lot of value in the comments of the surveyor performing the valuation that they commission as part of the mortgage application process. If the surveyor determines that a more thorough structural survey is needed, then the lender will require that the applicant arrange this. The lender will then make their decision using the comments from the structural survey.

This means that even if the surveyor deems that the risk of structural weakness, poor insulation or the threat of damp can be addressed or does not challenge the current value of the property then the lender will still consider your application. However, if the survey finds evidence of structural weakness or dampness, you run the risk of your mortgage application being rejected. In this case, you may want to consider applying for a bridging loan.

If you’re buying a new build property, you need not worry whether there is a single brick layer. New builds are required to be built in line with modern building regulations, which prevent construction from using single skin brickwork.

Given single layer brick construction is found on Victorian buildings, some mortgage providers consider that they may have good future value. Some lenders include the location of the property as part of their assessment. This means that you should not give up hope just because you find out that at least one wall of the building you’d like to buy is constructed out of a single skin of brick. You may just need to find the right mortgage provider. The best way to find the right lender for a single skin building mortgage is by speaking to our team of independent mortgage brokers at John Charcol.

Are There Any Advantages to a Building Constructed with a Single Skin?

While single-skin construction may offer some advantages in specific contexts, it also comes with several limitations and considerations.


  1. Cost-effectiveness: single-skin construction can be more cost-effective compared to double-skin construction, as it requires fewer materials and labour to build. This can result in lower construction costs, making single-skin buildings more affordable, particularly for budget-conscious projects
  2. Simplicity and ease of construction: single-skin walls are simpler to construct than double-skin walls, as they involve fewer components and construction steps. This can lead to faster construction times and reduced labour costs, making single-skin construction appealing for projects with tight schedules or limited resources
  3. Space efficiency: single-skin construction can maximise interior floor space compared to double-skin construction, as it eliminates the need for additional wall thickness. This can be advantageous for projects where space optimisation is a priority, such as residential buildings or small-scale developments
  4. Adaptability: single-skin construction allows for greater flexibility in design and customisation, as there are fewer constraints imposed by wall thickness or insulation requirements. This flexibility can accommodate various architectural styles and building configurations, providing more options for customisation and adaptation to specific project needs
  5. Natural ventilation and thermal mass: in some climates, single-skin construction with materials such as brick or concrete can provide natural ventilation and thermal mass benefits. These materials can absorb and release heat slowly, helping to regulate indoor temperatures and reduce reliance on mechanical heating and cooling systems


Despite these advantages, it's important to note that single-skin construction also has significant limitations and considerations.


  1. Poor thermal performance: single-skin walls typically have poorer thermal performance compared to double-skin walls, as they lack insulation and air gaps that help reduce heat transfer. This can lead to increased energy consumption for heating and cooling, resulting in higher utility costs and reduced comfort for occupants
  2. Limited sound insulation: single-skin walls offer limited sound insulation compared to double-skin walls, making them less effective at reducing noise transmission between interior and exterior spaces. This can be a concern in urban or noisy environments where soundproofing is important for occupant comfort
  3. Moisture and weather resistance: single-skin walls may be more susceptible to moisture infiltration and weather damage compared to double-skin walls, particularly if they lack adequate weatherproofing or moisture barriers. This can lead to issues such as dampness, mould growth and structural deterioration over time
  4. Durability and longevity: single-skin construction may have reduced durability and longevity compared to double-skin construction, as it can be more prone to structural issues, wear and tear,and damage from environmental factors. Proper maintenance and periodic inspections are essential to ensure the longevity of single skin buildings

Overall, while single-skin construction offers advantages such as cost-effectiveness, simplicity, and flexibility, it also has significant drawbacks related to thermal performance, sound insulation, moisture resistance and durability. The suitability of single-skin construction depends on factors such as climate, building use, maintenance requirements and budget constraints. Therefore, it's essential to carefully evaluate these factors before deciding on the appropriate construction method for a project.

Buy-to-Let Mortgages on Single Brick Buildings

Every lender has different criteria when considering granting a mortgage for a single brick buy-to-let property. They may require that no more than 25% of the external walls are constructed with a single brick layer - such as the end wall of a Victorian terraced building. That said, the nature of the construction of the building is only one factor among many others that they consider when reviewing the mortgage application. There are other standard criteria, such as the buyer’s credit history, income, as well as other aspects of the property, such as its location and the surveyor’s report.

Which Mortgage Lenders Will Consider a Single Brick Construction Property?

A popular misconception is that properties on 2 storeys with at least one external wall built in a half brick style are unmortgageable. This is not true, there are multiple single brick construction mortgage lenders. It is possible to find a high street lender who will grant a mortgage application, including some that will consider a 2 storey property which includes a half brick construction.

The following mortgage providers will consider a 2 floor building on its merits, subject to the valuation survey as well as whether the property is in keeping with other properties in the neighbourhood.

  • Nationwide
  • The Mortgage Works
  • Halifax
  • Birmingham Midshires
  • Royal Bank of Scotland
  • NatWest
  • Atom Bank
  • Santander
  • Skipton Building Society

Meanwhile, the following lenders will look at single storey buildings which include an external wall constructed out of a single layer of brick:

  • Bank of Ireland
  • Coventry/Godiva
  • Fleet Mortgages
  • Leeds Building Society
  • TSB
  • Virgin Money
  • Accord

How Do You Insulate a Single Brick Wall?

It’s often recommended that you install some insulation when you buy a single brick wall property.

There are 2 types of insulation you can add to a single brick wall: internal insulation or external. Let’s weigh up the pros and cons of each.

The advantage of insulating the inside of your single brick wall is that you don’t change the external look of the building. This means there are no planning permission issues. You are likely to lose a few centimetres inside each room, but you’ll end up with rooms that are easier to heat, and less prone to damp and condensation. Internal insulation is ideal for houses which have a solid wall of brick, stone, or slate for an external wall. Insulating internal walls is cheaper than adding external wall insulation and can be combined with a house redecoration. Alternatively, you can do each room step by step. The benefit of savings on energy costs makes internal wall insulation the obvious choice.

Adding insulation to your external walls can lead to a whopping 35% saving on your energy bills. While adding insulation to the internal walls insulates the inner wall, external wall insulation creates a barrier between your property’s external walls and the weather outside. To insulate the external walls, you’d need to add insulation boards to the wall. Typically, you’d use PIR boards, which are easy to install. This does mean that the outside walls of your home will change visibly. You do not need to apply for planning permission to add external insulation unless you live in a conservation area or if your property is a listed building.

If you’re required to use brick for your additional external wall, you may run into several challenges. You may need to extend the foundations of the building and find suitable and sufficient wall ties to connect your new wall with the existing wall. You may also have to replace all the doors and windows, as well as the roof, unless the roof already had a large overhang.

Other Eligibility Factors

If you’re set on buying a property which has at least one wall made of a solid wall, it will likely be classified as a non-standard property by mortgage lenders. It's therefore vital that you meet the lender’s other eligibility criteria. The risk is that you may not be offered the most competitive rates, or your application may be rejected.

The key criteria are:

  • Deposit size - the larger the deposit you can find, the better your chances of getting the most competitive interest rates. In the case of a single skin building, some lenders will require that you put down a larger than usual deposit
  • Your expenditure - the mortgage lender will want to make a careful assessment of your outgoings, including your debts and regular payments, as well as the number of dependents you have
  • Credit rating - having a good credit history will boost your chances of a successful mortgage application. Even if you have a bad credit history, you can still find a mortgage through an adverse credit lender. However, you may not find the most competitive market rates
  • Age - if you’re buying a property later in life, bear in mind that many mortgage lenders have a maximum age limit at the end of the mortgage term. However, some lenders are more flexible than others, and it’s even possible to find a mortgage if you are a pensioner

If there are any issues with the above eligibility criteria and you’re planning to buy a property with a single skin wall, you’ll need to get specialist advice. While the number of lenders willing to take you on will undoubtedly reduce, it’s still possible to find a lender if you use a broker like John Charcol.

If you have any questions about mortgages on single brick layer properties, get in touch with our independent mortgage experts. At John Charcol, we have access to a huge range of mortgage products and lenders, including mortgages for underpinned properties. We can help you find the right mortgage for your circumstances. Contact us today on 0330 433 2927 or submit an online enquiry to find out more.