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Downham Market, Norfolk

Semi-detached rear extension in Downham Market

For homes in Downham Market, a semi-detached rear extension is often the simplest way to gain space without moving. Single or two-storey extensions for semi-detached houses, with side access and one party wall. We take it from survey to completion certificate.

We cover Downham Market (PE38) as part of our Norfolk work. In Downham Market we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.

Book a free site visit

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

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

Guide prices for a semi-detached rear extension in Downham Market start from our East of England rate of £2,010–£3,290 per square metre, including VAT. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.

Semi-detached rear extension prices in Downham Market
SizeGuide price inc VAT
3 m wide × 4 m deep (12 m²)£24,000–£39,500
4 m wide × 5 m deep (20 m²)£40,500–£65,500
4 m wide × 6 m deep (24 m²)£48,500–£79,000

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 Downham Market?

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

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.

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 Downham Market like to extend?

Downham Market 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 Downham Market 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. Drawings and budget

    Floor plans and elevations for the options, each with a guide price.

  3. Paperwork handled

    Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.

  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 Downham Market

Neighbouring places we cover include King's Lynn (10.0 miles) and Wisbech (10.3 miles).

Other work in Downham Market:

All rear extensions in Downham Market

FAQ

Semi-detached rear extension questions in Downham Market

Can I live at home while the extension is built?

Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.

What postcode areas do you cover around Downham Market?

Including PE38, and the surrounding Norfolk area.

Can I match pebbledash or render?

Yes. Many semis are refinished with new render across the whole back elevation so old and new match.

Can you match the brick or stone on my Downham Market house?

We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.

Can I get a price without a visit?

Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.

Who will build my extension?

Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.

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.

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