Rear extension design, approvals and build across the UKCall 0800 088 6341 · Online guide price
Rear Extensionsrear-extensions.co.uk 0800 088 6341 Get a guide price

Greater London

Rear extensions in Upminster

From the first measured visit to building control sign-off, we handle rear extensions in Upminster under one contract.

Upminster is in Greater London, with postcode districts including RM11, RM12 and RM14. The nearest places we also cover are Emerson Park (1.7 miles) and Hornchurch (1.7 miles).

Book a free site visit

Tell us about the house and we'll call to arrange a free, no-obligation visit.

Rear extensions we build in Upminster

Also available across Greater London:

Rear extension prices in Upminster

London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.

ExampleGuide inc VAT
Single-storey, 3 m × 4 m (12 m²)£29,500–£48,500
Single-storey, 4 m × 6 m (24 m²)£59,500–£96,500
Two-storey, 3 m × 5 m footprint (30 m²)£70,000–£105,500
Side return, about 14 m²£42,000–£69,000
Wraparound, about 25 m²£71,500–£117,000

What are homes in Upminster like to extend?

Upminster is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.

Planning rules for Upminster

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.

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.

Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.

Nearby towns

FAQ

Questions people ask

How much is a rear extension in Upminster?

A 3 m × 4 m single-storey rear extension is about £29,500–£48,500 including VAT at our London guide rates; the written price follows a survey.

Do I need planning permission in Upminster?

Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.

Is the site visit in Upminster free?

Yes, with no obligation.

Do I need a party wall agreement?

In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

CallGuide price