Many UK homes will have flat roofs either on the whole property, or partially. Given the popularity of home extensions over the last few decades, flat roofs are extremely common. However, this can occasionally cause issues with insurance, meaning some lenders might be reluctant to approve a mortgage.

Yes, you can get a mortgage on a house with a flat roof. However, the right type of mortgage might be hard to find due to it possibly being classed as a non-standard construction property. It’s important to use a specialist independent mortgage adviser who understands this market, and the available lenders.

Should you buy a house with a flat roof?

There is no reason why you shouldn’t, but they don’t always come with a great reputation and can cause problems with insurance cover.

That can lead to problems in finding a mortgage lender prepared to offer you a flat roof extension mortgage.


It’s because lenders can have concerns that flat roofs and non-standard construction features could be hard to sell on should the property be repossessed in the future.

Flat roof extension mortgages

Depending on what type of property it is, the mortgage lender could ask you to have a roof inspection performed by a qualified surveyor.

Lenders can also place a limit on the total area of the house that can be flat in their mortgage terms.

On the other hand, there are mortgage lenders in the market who have no problem at all offering a mortgage on a house which has 100% flat roofing.

Our independent advisers have access to a wide range of lenders who offer flat roof mortgage products. By calling us and arrange a consultation, they will explore the entire market to find the most suitable deal for you. 

Buying a house with a flat roof extension

If you have a mortgage approved in principal, you need to make some checks before you go ahead with the house purchase. 

One way you can have that peace of mind is to arrange an independent building survey with a RICS surveyor.

They will be able to check for any problems with the roof ensuring that there are no risks in the structure, and no existing damage or potential problems further down the line.

They will check for:

  • Quality of the workmanship and structure
  • Ponding and water pooling
  • Thermal movement stress
  • Blistering and flashing 

Advantages to flat roofs

Flat roofs are quick to build and use cheaper materials, meaning they are very popular in the UK. Here are just some pros to why they might be on a house you are looking to get a mortgage on: 

  • Flat roofs are cheaper and quicker to build
  • They can save on space as there is no sloping ceiling
  • They can be more accessible and can be used as a balcony 

Disadvantages to flat roofs

In the main, flat roofs don’t tend to last as long as pitched roofs and will need to be regularly maintained.

The problems that can occur with flat roofs include:

  • Ponding water which can lead to leaks, moss, and algae growth
  • Debris can gather which will block drainage and hold moisture
  • Cracks and bubbles can appear leading to leaks
  • Flat roofs can shift and buckle over time
  • They can be poorly insulated and lose heat
  • They can also absorb heat leading to a very hot room in summer months
  • They can provide easy access to criminals leading to increased insurance costs

You should make sure that the roof is regularly inspected to clear any debris, check for damage, and ensure the drainage is working properly.

If your flat roof is damaged, it can be more expensive to repair than a pitched one. In many cases it’s not just about replacing a tile or two, but instead the whole area.

As a buyer, factor potential maintenance and repair costs into your decision, possibly using it as leverage in your purchase price.

What you should do next

If you have been turned down by a mortgage company on a house with a flat roof, get in touch with us today.

We have a large panel of independent mortgage specialists who can search the whole UK market and are experts in placing niche mortgage applications.