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Exeter, Devon

Semi-detached rear extension in Exeter

We plan and build rear extensions for semi-detached houses for homeowners in Exeter. Single or two-storey extensions for semi-detached houses, with side access and one party wall. Start with a free site visit, then a written price once the design is agreed.

Exeter sits in Devon, with postcode districts including EX1, EX2, EX3 and EX4. In Exeter 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 Exeter?

In Exeter, our guide for a semi-detached rear extension is £1,980–£3,220 per square metre including VAT for a standard specification. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.

Semi-detached rear extension prices in Exeter
SizeGuide price inc VAT
3 m wide × 4 m deep (12 m²)£23,500–£38,500
4 m wide × 5 m deep (20 m²)£39,500–£64,500
4 m wide × 6 m deep (24 m²)£47,500–£77,500

We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.

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

The planning route for a semi-detached rear extension in Exeter is set by England's householder rules and your council.

English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres 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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.

What are homes in Exeter like to extend?

Stone-built and rendered houses are common around Exeter, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.

How a semi-detached rear extension in Exeter 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. 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. 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 Exeter

Close by, we work in Heavitree, about 1.4 miles away, and Exmouth, about 9.2 miles away.

Other work in Exeter:

All rear extensions in Exeter

FAQ

Semi-detached rear extension questions in Exeter

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

As a guide, £1,980–£3,220 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £23,500–£38,500 at that rate. Your written price follows the survey.

How long does a rear extension take to build in Exeter?

Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.

How far can I extend a semi without planning?

3 metres under permitted development in England, or up to 6 metres with prior approval, outside designated land.

Do you handle building control in Exeter?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

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.

What postcode areas do you cover around Exeter?

Including EX1, EX2, EX3 and EX4, and the surrounding Devon area.

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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