Single Storey Extensions · London
The most popular home improvement in London for good reason. A single storey extension gives you the extra space your family needs without the complexity or cost of building upwards. We design and manage the whole process.
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What We Design
A single storey extension is the fastest, most cost-effective way to gain serious space in your home. Whether you need a bigger kitchen, an open-plan living area, or a new room that connects properly to your garden, a ground floor extension delivers it without the disruption of building a second storey.
Most of the single storey extensions we design in London are rear extensions - pushing out into the garden to create an open-plan kitchen, dining and living space. But we also design side return extensions on terraced houses, wrap-around extensions that combine both, and occasionally infill extensions that make use of awkward gaps between buildings.
The best thing about a single storey extension is that many of them can be built under Permitted Development rights, which means no planning application needed. That saves you 8 to 12 weeks of waiting and the uncertainty that comes with it.
Costs and Value
We are upfront about costs because we know it is the first question on everyone's mind. A single storey extension in London typically costs between £2,000 and £3,000 per square metre for construction. That means a 15 square metre rear extension will usually cost £35,000 to £50,000 to build, while a 25 square metre wrap-around might come in at £55,000 to £80,000.
On top of the build cost, you will need to budget for professional fees - architecture, structural engineering and building regulations. These usually add 10 to 15 percent to the total project cost. We give you a clear breakdown at the consultation stage so there are no surprises later.
For a detailed breakdown of what different extension types cost in London right now, read our house extension cost guide.
The value a single storey extension adds to your home typically exceeds the cost of building it. In London, a well-designed ground floor extension adds 5 to 8 percent to your property value - and in many boroughs, significantly more. Beyond the numbers, you get a home that actually works for how you live.
Planning
One of the biggest advantages of a single storey extension is that many can be built without planning permission. Under standard Permitted Development rights, you can extend up to 3 metres from the rear wall of a semi-detached or terraced house, or 4 metres from a detached house.
Under the Larger Home Extension scheme (prior approval), these limits increase to 6 metres and 8 metres respectively. This is a notification process rather than a full planning application - it is faster and there is no risk of refusal on design grounds, only neighbour impact.
If your extension goes beyond these limits, or your property is in a conservation area with restricted PD rights, you will need full planning permission. This is not a problem - it just means we need to submit an application, which typically takes 8 to 12 weeks for a decision.
We assess the planning route at the start of every project. Whether it is PD or full planning, we handle the entire process so you do not need to deal with the council directly.
How It Works
01
Consultation
We visit your home, understand your brief, and give you an honest assessment of what is achievable - including the planning route, likely costs and realistic timescales.
02
Design
We develop the design with you, exploring layout options and materials until we land on a scheme that works for your home and your budget.
03
Planning
We manage the planning application or Permitted Development notification on your behalf - dealing with the council, neighbours and any conditions that arise.
04
Build
We produce detailed construction drawings and, where needed, oversee the build to ensure the finished extension matches the design - on time and on budget.
Common Questions
