Extending your home in Devon
Every type of house extension in Devon, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Towns listed9
- Price regionSouth West England (×1.02)
- Planning rulesEngland
- Postcode districts59
Towns we cover in Devon
Towns we cover here include Plymouth, Exeter, Paignton, Torquay.
Popular extension prices in Devon
Every figure below is a guide for Devon, adjusted for South West England build costs (×1.02) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Single-storey rear extensions | 20 m² | £41,500 – £53,500 |
| Orangery extensions | 16 m² | £45,500 – £57,500 |
| Kitchen extensions | 20 m² | £42,500 – £54,500 |
| Conservatory replacement extensions | 14 m² | £30,500 – £39,500 |
| Side return extensions | 11 m² | £26,500 – £34,000 |
| Double-storey extensions | 32 m² | £58,500 – £77,000 |
Planning rules in Devon
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Choosing the right extension in Devon
South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
For many houses here, annexe extensions, single-storey rear extensions or orangery extensions gives the most useful space for the budget.
All extension types we build in Devon
- Building regulations for extensions · from £900
- Conservatory replacement extensions · from £20,000
- Side extensions · from £22,000
- Flat roof extensions · from £21,000
- Bedroom extensions · from £26,500
- Double-storey extensions · from £38,500
- Orangery extensions · from £30,500
- Wraparound extensions · from £36,500
- Annexe extensions · from £56,000
- Pitched roof extensions · from £22,500
- Side return extensions · from £18,000
- Single-storey rear extensions · from £21,000
- Glass box extensions · from £30,500
- Extension plans and drawings · from £1,200
- Home office extensions · from £16,000
- Timber frame extensions · from £21,000
- Kitchen extensions · from £27,500
- Planning permission for extensions · from £350
- Utility and boot room extensions · from £14,000
- Bungalow extensions · from £26,500
- Extensions over a garage · from £24,000
- Porch extensions · from £4,050
Questions about extensions in Devon
How much does an extension cost in Devon?
With our South West England factor (×1.02), a standard-spec 20 m² single-storey extension is a guide £41,500 to £53,500 including VAT. Prices for every type are linked on this page.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do you cover all of Devon?
Yes, across the whole of Devon. Site visits are free and there is no obligation.
How long does an extension take in Devon?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Book a free site visit in Devon
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.