Semi-detached rear extension in Addlestone

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

For Addlestone we work from the South East England rate: £2,130–£3,470 per square metre of new floor, including VAT, standard specification. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.

Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.

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

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

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.

A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.

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 Addlestone like to extend?

Around Addlestone the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.

How a semi-detached rear extension in Addlestone comes together

1. Look round and measure

   A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.

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. Approvals

   Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

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 Addlestone

Neighbouring places we cover include Chertsey (1.3 miles) and Weybridge (1.5 miles).

• Semi-detached rear extension in Chertsey
• Semi-detached rear extension in Weybridge
• Semi-detached rear extension in Shepperton
• Semi-detached rear extension in Walton-on-Thames
• Semi-detached rear extension in Sunbury-on-Thames

Other work in Addlestone:

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

All rear extensions in Addlestone