If you want to expand your home, one of your options is to build a flat roof extension. But with so many home expansion possibilities available, like conservatories, orangeries and catslide roofs, it can be hard to know whether this is the right choice for you. So to showcase the benefits of a flat roof and how they could improve your home, we’ve come up with 5 reasons why you should build one.
1. Provides double the space
Needless to say, people build extensions to create more space. What makes flat roof extensions stand out from other types of extension is that they provide double the space they take up. This is because the area on top of the roof is as useful as the space beneath it.
Reinforce your roof and turn it into a first floor roof terrace. This creates double the living space than an extension with a pitched roof and compensates for any space you might have pinched from the garden.
2. Cheaper

Another bonus to flat roof extensions is that they’re usually cheaper than extensions with pitched roofs. This is for the simple reason that flat roofs use more materials than pitched roofs. Of course, you still need to invest in your flat roof. Cheap flat roofs don’t last long and their repair bill can rack up. But if you go for a good quality flat roof you can be pretty sure that you’re getting a roof that will last for a long time and is cheaper than most.
3. Increased flexibility
You should also consider building a flat roof extension because of the increased flexibility they offer. The design of extensions with pitched roofs tends to orientate around supporting them. Flat roofs, on the other hand, require much less structural reinforcement. This means that you’re free to experiment with less traditional extension shapes and floor plans if you choose to build a flat roof extension.
4. Has eco options
If you want to make your home more eco, building a flat roof extension is a good way to go. You have the option to give it a green roof by planting it with moss or grass. Green roofs are fairly expensive, as they require structural reinforcement, a root barrier and a specialised drainage system. However, if you choose to invest in one a green roof will help to reduce CO2 levels and provide great insulation for your extension.
5. Gives you glazing freedom
A big advantage to flat roof extensions is that they give you freedom to be creative with your glazing. You can install large amounts of glazing in a flat roof if you wish, more than pitched roofs allow. Plus, you can choose where you want your glazing to go, which gives you much more flexibility than a conservatory would.
So there are plenty of reasons why building a flat roof extension could be a great way to expand your home. Simply click ‘Start my project’ and fill in our online form to get up to 4 quotes from reputable local builders. Or to find out about other types of extension, see our pages on catslide roofs and orangeries.
Price
From around £1,200 per square metre
Depending on location and materials
Installation time
Approx. 10+ weeks
Depending on location and size of extension
Advantages and disadvantages
- Provides double the space of a pitched roof extension
- Often cheaper than extensions with pitched roofs
- Has flexible design
- Has eco options
- Easy to add glazing in different places
- More hassle to build than a conservatory
- Reinforcing flat roofs can be expensive