Balham, Greater London
Two-storey rear extension in Balham
For homes in Balham, a two-storey rear extension is often the simplest way to gain space without moving. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. We take it from survey to completion certificate.
Balham and its postcode districts SW4, SW11 and SW12 are part of our Greater London coverage. In Balham, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Balham?
In Balham, our guide for a two-storey rear extension is £2,340–£3,510 per square metre including VAT for a standard specification. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £70,000–£105,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £112,500–£168,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a two-storey rear extension in Balham?
The planning route for a two-storey rear extension in Balham is set by England's householder rules and your council.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Balham like to extend?
Much of Balham is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.
How a two-storey rear extension in Balham comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Two-storey rear extensions near Balham
Neighbouring places we cover include Brixton Hill (1.2 miles) and Earlsfield (1.5 miles).
- Two-storey rear extension in Brixton Hill
- Two-storey rear extension in Earlsfield
- Two-storey rear extension in Streatham
- Two-storey rear extension in Furzedown
- Two-storey rear extension in Battersea
Other work in Balham:
FAQ
Two-storey rear extension questions in Balham
How long does a rear extension take to build in Balham?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
How much does a two-storey rear extension cost in Balham?
As a guide, £2,340–£3,510 per square metre including VAT for a standard specification. For example, 3 m × 5 m footprint, two floors (30 m²): about £70,000–£105,500 at that rate. Your written price follows the survey.
Is two-storey cheaper per square metre than single-storey?
Usually yes, because the foundations and roof are shared across twice the floor area. The total cost is higher.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
What postcode areas do you cover around Balham?
Including SW4, SW11 and SW12, and the surrounding Greater London area.