Trowbridge, Wiltshire
Single-storey rear extension in Trowbridge
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. If you live in Trowbridge and want to know what a single-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Trowbridge and its postcode districts BA14 are part of our Wiltshire coverage. A single-storey rear extension in Trowbridge is mostly built from the garden side, so the house stays usable for most of the job.
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 single-storey rear extension cost in Trowbridge?
In Trowbridge, our guide for a single-storey 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.
| Size | Guide 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a single-storey rear extension in Trowbridge?
The planning route for a single-storey rear extension in Trowbridge is set by England's householder rules and your council.
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.
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. 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 Trowbridge like to extend?
Trowbridge has Victorian terraces nearer the centre and post-war semis on the edges. Sloping gardens are frequent, which affects floor levels and steps down to the patio.
How a single-storey rear extension in Trowbridge comes together
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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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.
Single-storey rear extensions near Trowbridge
We also build single-storey rear extensions in nearby Westbury (4.2 miles) and Melksham (4.8 miles).
- Single-storey rear extension in Westbury
- Single-storey rear extension in Melksham
- Single-storey rear extension in Neston
- Single-storey rear extension in Bath
- Single-storey rear extension in Frome
Other work in Trowbridge:
FAQ
Single-storey rear extension questions in Trowbridge
What postcode areas do you cover around Trowbridge?
Including BA14, and the surrounding Wiltshire area.
Do you handle building control in Trowbridge?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Does it add value to the house?
Nationwide's October 2025 house price research found that a 10% increase in floor area is linked to about 5% higher value on average. It is a guide, not a promise; local agents can tell you what extended homes on your street sell for.
Is the site visit in Trowbridge free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can you match the brick or stone on my Trowbridge house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need planning permission for a rear extension in Trowbridge?
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.