Side extensions for homes in Devon
A side extension in Devon starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide priceFrom £22,000 inc VAT
- PlanningSingle storey can be permitted development
- Towns covered9
- Site visitFree, no obligation
What should I budget for a side extension in Devon?
Prices below are for Devon, using the South West England factor of ×1.02. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Devon: £1,780 to £3,470 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £22,000 – £27,000 | £25,000 – £32,500 | £31,500 – £42,000 |
| 3 m × 6 m 18 m² | £32,000 – £39,000 | £37,500 – £49,000 | £47,500 – £62,500 |
| 3 m × 8 m 24 m² | £42,500 – £51,500 | £50,000 – £65,000 | £63,500 – £83,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Included in a typical project
- Planning route checked or application made
- New openings through the side wall
- Structure, roof tied into the house
- Windows, doors and finishes to match
- Foundations near boundaries and any drains
- Survey, design and street-view drawings
Local to Devon
Towns we cover in Devon include Plymouth, Exeter, Paignton, Torquay, Newton Abbot, Exmouth, Barnstaple, Bideford. In the South West, local stone, render and brick vary from town to town, so matching materials is a big part of designing an extension that looks right.
Planning rules that apply in Devon
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
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 over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Devon home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Devon
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Devon, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a side extension in Devon?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do I need building regulations approval in Devon?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I build a side extension without planning permission?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a planning application.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
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.