One of the first major design decisions you’ll have to make when extending your home is whether to use a flat roof or a pitched roof for your extension. While there’s no straightforward answer to which one is best, there are important benefits and drawbacks to each option. In this article, our London-based home renovation team looks at what to consider in the pitched roof vs flat roof decision-making process, so you get the best option for your property.

Pitched Roofs – The Pros and Cons

Pitched Roof Extension in London

A pitched roof is any roof that has a peak, creating that distinctive triangular shape we all know so well.

Here’s what we like about this design:

  • Traditional aesthetics – This is the most traditional roof shape, making it settle easily into neighbourhoods with a similar aesthetic. If your home already has a pitched roof, a pitched roof on your extension will make it look like a natural part of the existing structure. It may also be required in certain listed buildings and areas.
  • Natural light – By creating a higher roof, you can also maximise the amount of natural light into the building, especially if you combine this with roof lighting in the apex of the triangle you create. This brings in a lot of sunlight by accommodating the angle of the sun throughout the day.
  • More volume indoors – If you leave the vault of the pitched roof exposed in your design, you get a much more spacious extension. You can use this to create a dramatic feature in your room, add a loft space, or place larger, more dramatic light fixtures to create a focal point.
  • Greater longevity – Pitched roofs require strong materials, greater labour, and design, so they tend to last much longer and require less maintenance. This is also because they naturally shed water and snow more easily, reducing the risks of damp and moisture damage.

But this type of roof design also comes with several drawbacks to consider:

  • More costly to build – Because of the design, materials, and labour needed to build this type of roof, pitched roofs are more expensive and take longer to build.
  • Intrusive – Pitched roofs don’t always suit the existing building and can infringe on upstairs windows or balcony structures. They may also impact your home’s view or the view of neighbouring homes.
  • Style – If your home already has a flat roof or a distinct style, a pitched roof can look out of place if added onto your home.

You can see the look and benefits of pitched roof extensions for yourself in some of our favourite projects, including this home kitchen extension in Isleworth, this traditional pitched roof extension in Battersea, and this open-plan living space in East Dulwich.

Flat Roofs – The Pros and Cons

Flat Roof Extension in London

Flat roofs have a lot to offer in a home extension and have come a long way in terms of their style and build quality, especially if installed by a specialist team.

What we love about flat roof extensions:

  • Affordability – Flat roof extensions are straightforward and simple to install, so the costs are much lower than with a pitched roof. Even when using a specialist design and construction team, it will usually be a very cost-effective option.
  • Skylights – There are some very high-quality skylights specifically designed for flat roofs that allow you to bring in a lot of natural light. There is a greater variety of skylights for flat roofs, and they can be individual or run the length of an extension, forming a structural as well as an aesthetic part of the roof design.
  • Versatile – Flat roof extensions, when designed properly, can look great on almost any type of existing architecture. You can design it to create a modern feature that contrasts against traditional architecture or make it look like a seamless addition to the home.
  • Non-intrusive – A flat roof extension can be designed not to intrude on the views or sunlight into the upper storeys of the home and won’t intrude on neighbouring views or structures as they will be level with the existing walls. You can also plant them up with wildflowers to make them sink into the natural surroundings even more.

As with pitched roofs, there are several drawbacks to consider:

  • Lower ceiling – A standard flat roof extension will naturally create a lower internal ceiling. This should be designed to comfortably accommodate your living space, but you won’t have the high-volume space of a pitched roof.
  • Higher maintenance – Today’s flat roofs use very high-quality materials, including waterproofing, and are designed with a slope to help shed water effectively. However, it is likely that your roof will need more maintenance in the long-term to keep it in perfect condition and prevent water ingress.
  • Lower efficiency – Pitched roofs can naturally accommodate more insulation, so they are a better energy efficiency option than flat roofs. This may impact your energy bills, but a good team should be able to optimise the energy efficiency of your flat roof extension.

You can see the versatility and benefits of flat roof extensions in some of our most elegant projects, including this modern glass roof extension in Richmond Upon Thames, an industrial-chic extension in Thames Ditton, and a contemporary addition to a Victorian terrace in Tooting.

We hope you enjoyed our input into the flat roof vs pitched roof debate and got the information you need to design your dream home. 

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End-to-end Design and Construction Services for Your Home Extension

PlusRooms is a leading design and construction firm in London that specialises in custom property extensions, using flat, pitched, crown, and combination roof options. Our talented team will lead you through the process from start to finish, guiding you in making the choice on flat roofs vs pitched roofs, and helping you get the best floorplan, features, and quality for your budget. Whether you want a home for entertaining, for family living, or for your own enjoyment and investment purposes, we’re here to make that dream come true. In over 17 years we’ve helped over 1,400 homeowners transform their houses – contact us and let’s see what we can do for you.