Semi-detached rear extension in Upminster

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

Guide prices for a semi-detached rear extension in Upminster start from our London rate of £2,470–£4,030 per square metre, including VAT. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.

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 Upminster?

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

In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part 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 Upminster like to extend?

Much of Upminster is 1920s and 1930s semis and short terraces with longer gardens than inner London, which suit full-width single-storey rear extensions. Parking suspensions, skip licences and controlled hours on residential streets shape the programme more than the build itself.

How a semi-detached rear extension in Upminster 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. Approvals

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

4. 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.

Semi-detached rear extensions near Upminster

From Upminster, the nearest places we also cover are Emerson Park (1.7 miles) and Hornchurch (1.7 miles).

• Semi-detached rear extension in Emerson Park
• Semi-detached rear extension in Hornchurch
• Semi-detached rear extension in Elm Park
• Semi-detached rear extension in Harold Wood
• Semi-detached rear extension in Romford

Other work in Upminster:

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

All rear extensions in Upminster