Semi-detached rear extension in Streatham

How much does a semi-detached rear extension cost in Streatham?

In Streatham, our guide for a semi-detached rear extension is £2,470–£4,030 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.

These are guide ranges; the written quote after the survey is the figure that counts.

Do you need planning permission for a semi-detached rear extension in Streatham?

Here is how the rules in England apply to a semi-detached rear extension in Streatham.

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.

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.

England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.

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 Streatham like to extend?

Much of Streatham 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 semi-detached rear extension in Streatham comes together

1. Survey visit

   We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.

2. Design and guide price

   Two or three layout options with a guide price for each, so you choose the design knowing what it costs.

3. Planning and regulations

   We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.

4. 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.

Semi-detached rear extensions near Streatham

We also build rear extensions for semi-detached houses in nearby Furzedown (0.7 miles) and Norbury (1.1 miles).

• Semi-detached rear extension in Furzedown
• Semi-detached rear extension in Norbury
• Semi-detached rear extension in Tooting
• Semi-detached rear extension in Brixton Hill
• Semi-detached rear extension in Balham

Other work in Streatham:

• Single-storey rear extension
• Two-storey rear extension
• Kitchen-diner rear extension
• Side return extension
• Wraparound extension
• Glazed rear extension

All rear extensions in Streatham