When you’re planning your home extension, it’s easy to get caught up in all of the ‘fun’ elements, such as picking out your furniture and décor, or perhaps designing your new kitchen. It’s less easy to get excited about the more structural elements, such as the type of roof you’re going to have; but, the roof will define the overall look of your extension.
Here we look at the pros and cons of the two main choices when deciding on a roof type:
- Flat roof extension
- Pitched roof extension
Flat Roof Extension
Flat roofs are commonly used in extensions – especially single-story ones. Working out if a flat roof is better than a pitched roof is not that straight forward as it depends on the look you want to achieve and your budget. Here are the pros and cons of flat roofs:
Pros
- Costs: The obvious benefit of a flat roof is cost, as they are generally cheaper than an extension with a pitched roof. This is because there is less structural engineering involved and they are, for the most part, constructed from cheaper materials
- More contemporary – flat roofs can have a great modern look; perfect for more contemporary buildings – although some more contemporary materials, such as zinc or optional cladding, can bring the costs up
- Skylights and light wells – flat roof can incorporate important design elements, such as skylights and light wells
- Despite the name, flat roofs do have a slight pitch to them, so rainwater will run off.
Cons
- The ceiling inside will be lower, making the space appear smaller
- A flat roof can require more maintenance over time, depending on the materials used
- Their lifespan tends to be shorter than pitched roofs
- Flat roofs are also not the most energy efficient form of design.
How Much Does A Flat Roof Extension Cost?
The cost of a flat roof extension depends on the type of extension you are going for. This can range from… £30K to £75K and above, but this is dependent on many different factors, such as the size of the flat roof extension.
Weighing up a flat roof for your extension? Get a free, no-obligation quote for your home – call us on 0203 285 7357 or request a callback.
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Flat roof extension London
Flat roof extensions are a popular choice in London – this cost-effective option can give a contemporary juxtaposition to a period property. While they don’t have the same lifespan as a pitched roof, the development of new materials means that a flat roof now might have a lifespan of around thirty years. However, the amount of time that a flat roof will last for will be down to the materials used and the level of workmanship.
Flat roof extension ideas
Flat roof extensions are ideal for small structures as they save space and, contrary to what most people believe. A flat roof extension should always have a slight pitch to enable rainwater to drain. If you decide to opt for a flat roof extension, it is still possible to install design features such as skylights and light wells and you may even be able take advantage of the design to create a roof terrace – giving you more outdoor space (This will need to be specified during the design process and is subject to planning approval).
For inspiration on how your extension could look, take a look at our case studies below, including many of the best modern flat roof extension design ideas:
You can now download this information in a handy pdf guide
Rosebery Road, Haringey Flat Roof Extension
This North London home has been transformed with a flat roof side extension. Light wells, made of reinforced glass, were installed to ensure that plenty of light penetrates the room. The extra space has been used to create a large kitchen diner and a roof terrace on top of the extension roof. This feature has also allowed more natural light to enter a pre-existing bedroom.
Kings Road, Kingston-on-Thames Flat Roof Extension
The owners of this South West London home have added a flat roof kitchen extension to their home to create a spacious and light kitchen diner. The floor to ceiling bi-folding doors give a seamless feel between the garden and the kitchen. Skylights have been installed over the dining table to let in as much daylight as possible.
Colyton Road, Dulwich Southwark Flat Roof Extension
This modern flat roof extension located in Dulwich; South London has incorporated design features that allow as much light as possible to enter the open plan living space. Picture bi-folding doors help to bring the outdoors in, and the three skylights offer, not just light, but also an interesting design feature.
Manor Grove, Richmond Flat Roof Extension
For this build in South West London, we demolished an existing kitchen extension and built a modern flat roof extension to open up the rear of the house. Our team transformed this space into a kitchen diner that overlooks their landscaped garden, which we also created. Four skylights and two French windows give the room a light and spacious feel and connect the space to the garden.
Like the look of a flat roof extension? Get a free, no-obligation quote for your home – call us on 0203 285 7357 or request a callback.
Pitched roof extension
Pitched roofs are not always used for small structures like extensions as they tend to cost more. However, some of our clients have opted for pitched roofs as they do have their benefits. Here are the pros and cons of pitched roof extensions:
Pros
- The design of a pitched roof will usually blend in better with the style of more traditional houses, making it a favourite with planning departments.
- Higher ceilings: a pitched roof gives you more height and can offer more architectural features, such as beams and a sloping ceiling.
- Longer lifespan: a pitched roof tends to have a longer lifespan than a flat roof, thanks to the design and the more weather resistant, durable materials that are used.
- A pitched roof will also allow for more insulation than a flat roof – helping to keep your energy bills down.
Cons
- Cost: a pitched roof is more expensive due to the level of structural engineering needed and the materials used.
- Pitched roofs generally take more time to build than flat roofs, which can mean more disruption and larger labour costs.
Our experts at Simply Extend can help you decide on the best option for you when planning your London home extension. Call us today on 0203 285 7357 or complete our online enquiry form.
How Much Does A Pitched Roof Extension Cost?
The cost of a pitched roof extension also depends on the type of extension to be built. The price can range between… £40K to £80K, and even above, but is mainly influenced by the size of the pitched roof extension to be built. Get a Free Quote.
Leaning towards a pitched roof extension? Get a free, no-obligation quote for your home – call us on 0203 285 7357 or request a callback.
“Simply Extend provided a very detailed quote with clarity on what was included and excluded in the cost. Fantastic customer service provided by Holly and Lorraine, who were both really helpful in addressing any issues or concerns we had.”
Tracey
The Woodlands, South London — Wrap Around Extension
“The team were on time and professional and provided some great design solutions I would not have thought of. I am really happy with the quality of the build and design which other tradesmen have also admired.”
Kirstin
Glendish Road, North London — Side Return Extension
“We’ve held back on writing our review until we’d had time to see how the workmanship stood up — and we can now safely report that the results are fantastic. No sagging, cracks or water ingress, and still looking great three years on. The team were punctual, polite and listened to any concerns we had.”
Melody & Ed
Sunny Bank Road, South Norwood — Extension
“The price was very competitive and the process made very easy. The Project Manager and build team were excellent, very responsive, on time, hard working and clean. They were great at providing options and advice to challenging design issues. We are very happy with the results and would recommend the team.”
Stuart
Scholars Road, Balham, South London — Wrap Around Extension
“Had an excellent kitchen extension built for us. Really happy with the results, it has truly transformed our home. The stress was taken out of it — we had a temporary kitchen so could cook and live as normal while the work was carried out. Very happy with our new, much larger and lighter kitchen and living space.”
Tim
South Norwood, South East London — Rear Extension
“They have done a lovely job, we’re still very pleased a year on. Excellent finish, and it shows that they paid attention to detail. Very pleasant people to work with, and a competitive price.”
Rachel
Grove Park, Camberwell, South East London — Rear Extension
“Simply have been fantastic from start to finish. From the technical drawings, architect’s work and building work to the legalities arranged on our behalf, we’ve been really impressed. Our project manager has gone over and above — his team have now become our go-to for any future work we need.”
Lucy
Chessington, Surrey — Rear Kitchen Extension
“We just finished a big kitchen extension and garden refurb. Our expectations were managed throughout the process, everybody very helpful and quick to react to issues. Excellent service from start to finish and some very, very hard working ground crew.”
Adam
Kensal Rise, North West London — Kitchen Extension
“From start to finish Simply Extend were fantastic. The whole job came out within budget and on time and the quality of work is exceptional. We are thrilled to bits with it — it now looks like it’s from a magazine. Heartily recommend.”
Mike
Minard Road, Lewisham — Rear Extension
“The end result is so much better than I ever hoped. The building team were all so great — always punctual and tidy. I never had to move out. The project was finished pretty much when expected. My doubting friends and family were also very impressed! I cannot recommend them highly enough.”
Dominique
Kingston, London — Rear Flat Extension
“Fantastic construction of a large single storey rear extension. The Simply team provided 110% customer care and after-sales help — a single point of contact through planning, architect’s designs, construction and final touches. Really pleased with the final outcome and attention to detail.”
Safdar
Woodmansterne Road, Streatham — Rear Extension
“It was a big project involving a lot of structural work, completed professionally, diligently and seamlessly. The team were easy to communicate with and gave much practical and experienced advice. We would highly recommend Simply Extend — they work hard, have a high standard and are trustworthy.”
Amanda & Jose
Brondesbury Road, West Kilburn — Rear Extension & Refurbishment
Pitched roof extension London
Whether you choose to opt for a pitched roof or must have one to comply with planning restrictions, pitched roof extensions in London do have the benefit of generally lasting longer than flat roof extensions and can be more aesthetically appealing. Popular for London's period properties where keeping the integrity of a building is paramount, a pitched roof extension can transform your home.
Pitched roof extension ideas
A pitched roof usually lasts longer and, depending on the look you want to achieve, can be more aesthetically pleasing. Some of our clients opt for pitched for design reasons, while for some it is a planning requirement. If your property is listed or in a conservation area, you may be asked to build an extension with a pitched roof to keep in line with the integrity of the building and area. Here are some ideas on what you can do with a pitched roof extension:
Richmond Road, Kingston Upon Thames, South West London
This ground floor flat was transformed by this pitched roof rear extension. Originally a one bedroom flat, by adding this extension and reconfiguring the property, we created an open plan kitchen and living area and then changed the old kitchen into a second bedroom. The pitched roof extension, which has three skylights installed as well as a large patio door, brings in plenty of light.
Danbrook Road, Streatham, South London
This delightful property in south london features a pitched roof extension that incorporates a living area that opens out into the garden. A pitched roof extension is not only for large properties but smaller ones too, this slimline home uses the space available to it wisely, while not compromising too much on precious outdoor space.
Gracefield Gardens, Streatham, South London
This high spec pitched roof extension gives the homeowners a seamless connection to the garden and incorporates the kitchen, a living space to relax in and a dining area. The sleek modern kitchen has clean lines and a standout extractor fan reflects light around the room. The owners have also opted to convert the loft at the same time, creating an additional double bedroom and ensuite bathroom.
Ready to talk through flat vs pitched for your home? Get a free, no-obligation quote - call us on 0203 285 7357 or request a callback.
FAQs
What is the cheapest roof for an extension?
There is no major difference between the cost of a pitched roof and a flat roof extension. A flat roof built from fibreglass or GRP will cost more than the typical flat roof felt material and can cost more than tiling on a pitched roof.
Can I have a pitched roof extension?
For most property extensions you can have a pitched roof extension, as they are allowed within permitted development. If you live within a conservation area or heritage zone, you may need to check with your local building authority or council if a pitched roof is allowed.
Do you need planning permission for a pitched roof on extension?
You could need planning permission for a pitched roof extension depending on the size of your extension and the location of your home. Parameters for planning permission for pitched roof extensions change between different councils and boroughs in the UK.
How much does a pitched roof extension cost?
A pitched roof rear extension will begin at approximately £35k including VAT for the smallest extension size. A side return pitched roof extension will cost upwards of approximately £45k, and a wrap-around pitched roof extension will start at approximately £55k.
How long do flat roof extensions last?
A flat roof extension will last for many years, however the material used on the roof has a typical lifespan of approximately 20 years. You may need to replace the roofing material after this time, depending on condition or any other damage.
Are flat roof extensions bad?
Flat roof extensions are not bad for your house. However, they are subject to a shorter lifespan than a pitched roof as water collects instead of draining off, corroding material. All building works have positives and negatives to their process of construction.
Which is better flat roof or pitched roof?
Typically, a pitched roof has a longer lifespan compared to a flat roof, as the water drains off the roof more efficiently than a flat roof extension. It is also a matter of personal preference on the aesthetic appearance of the two roof types.
Is a flat roof extension cheaper than a pitched roof?
A flat roof extension is not typically cheaper than a pitched roof, however this depends on the materials used. It can cost more to use GRP or fibreglass over the more commonly used felt material used on flat roof extensions.
How big can a flat roof extension be?
A flat roof extension can be up to 4m in size if you are working within permitted development restrictions. If you want to build a bigger flat roof extension, you can apply for planning permission from your local council for a fee.
Do you need planning permission for flat roof extension?
You could need planning permission for a flat roof extension depending on the size of your extension and the location of your home. Parameters for planning permission for flat roof extensions change between different councils and boroughs in the UK.
How much does a flat roof extension cost?
A flat roof rear extension will begin at approximately £35k including VAT for the smallest extension size. A side return flat roof extension will cost upwards of approximately £45k, and a wrap-around flat roof extension will start at approximately £55k.
Are flat roof extensions allowed?
Flat roof extensions are allowed on most properties, subject to planning restrictions set by your local building authority, typically your council. The only restrictions you will face will be a height restriction that applies to all extensions, with a flat or pitched roof.
