Side extensions in Brixton: design, approvals and build
Our design and build teams take on side extensions in Brixton, from the first measured survey through planning and building control to the finished room.
- Guide price in BrixtonFrom £28,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsSE5, SE24, SW2, SW4, SW8
Planning and approvals in Brixton
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Side extension prices in Brixton
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Brixton: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £28,500 – £34,500 | £31,500 – £41,500 | £40,500 – £53,500 |
| 3 m × 6 m 18 m² | £40,500 – £49,500 | £47,500 – £62,500 | £60,500 – £80,000 |
| 3 m × 8 m 24 m² | £54,500 – £66,000 | £63,500 – £83,000 | £81,000 – £106,500 |
Try the guide-price tool to see a range for your own size and finish.
When a side extension makes sense
- Homes needing a utility, study or ground-floor bedroom
- Houses where the rear garden is small
- Detached and semi-detached houses with side land
Councils often prefer side extensions to sit slightly back from the front of the house with a lower roof, so the original building still reads clearly. We design to those principles from the start to avoid redesigns.
Extensions in and around Brixton
Our survey diary covers Brixton, including SE5, SE24, SW2, SW4, SW8, SW9. The same team covers Peckham (2 miles), Battersea (2 miles), Streatham (3 miles), New Cross (3 miles), all within easy reach.
In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Side extension questions answered
Who do I contract with for a side extension in Brixton?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does a side extension take to build in Brixton?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
Will my neighbours in Brixton be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Can I build a side extension without planning permission?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a planning application.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
Book a free site visit in Brixton
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.