Furzedown, Greater London
Single-storey rear extension in Furzedown
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. If you live in Furzedown and want to know what a single-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Furzedown (SW12, SW16 and SW17) as part of our Greater London work. On Victorian and Edwardian terraces like those around Furzedown, a single-storey rear extension is usually the simplest way to fix a small back kitchen without touching the bedrooms.
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 single-storey rear extension cost in Furzedown?
For Furzedown we work from the London rate: £2,470–£4,030 per square metre of new floor, including VAT, 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 wide × 4 m deep (12 m²) | £29,500–£48,500 |
| 4 m wide × 5 m deep (20 m²) | £49,500–£80,500 |
| 4 m wide × 6 m deep (24 m²) | £59,500–£96,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a single-storey rear extension in Furzedown?
Here is how the rules in England apply to a single-storey rear extension in Furzedown.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Furzedown like to extend?
Much of Furzedown 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 single-storey rear extension in Furzedown comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Single-storey rear extensions near Furzedown
Neighbouring places we cover include Streatham (0.7 miles) and Tooting (0.8 miles).
- Single-storey rear extension in Streatham
- Single-storey rear extension in Tooting
- Single-storey rear extension in Norbury
- Single-storey rear extension in Balham
- Single-storey rear extension in Mitcham
Other work in Furzedown:
FAQ
Single-storey rear extension questions in Furzedown
What postcode areas do you cover around Furzedown?
Including SW12, SW16 and SW17, and the surrounding Greater London area.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Does it add value to the house?
Nationwide's October 2025 house price research found that a 10% increase in floor area is linked to about 5% higher value on average. It is a guide, not a promise; local agents can tell you what extended homes on your street sell for.
How much does a single-storey rear extension cost in Furzedown?
As a guide, £2,470–£4,030 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £29,500–£48,500 at that rate. Your written price follows the survey.
How long does a rear extension take to build in Furzedown?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.