Semi-detached rear extension in Flitwick

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

In Flitwick, our guide for a semi-detached rear extension is £2,010–£3,290 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.

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 semi-detached rear extension in Flitwick?

Planning for a semi-detached rear extension in Flitwick follows the English householder rules.

Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is 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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.

What are homes in Flitwick like to extend?

Flitwick mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.

How a semi-detached rear extension in Flitwick comes together

1. 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.

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. Fixed price and build

   A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.

Semi-detached rear extensions near Flitwick

We also build rear extensions for semi-detached houses in nearby Ampthill (1.6 miles) and Kempston Hardwick (6.0 miles).

• Semi-detached rear extension in Ampthill
• Semi-detached rear extension in Kempston Hardwick
• Semi-detached rear extension in Kempston
• Semi-detached rear extension in Dunstable
• Semi-detached rear extension in Henlow

Other work in Flitwick:

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

All rear extensions in Flitwick