Extensions over a garage for homes in Somerset
A over-garage extension in Somerset 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 £24,000 inc VAT
- PlanningHouseholder application needed
- Towns covered11
- Site visitFree, no obligation

Towns in Somerset
When an over-garage extension makes sense
- Homes where the landing can connect to the new room
- Detached and link-detached houses with an attached garage
- Families needing a bedroom without losing garden
Planning and approvals in Somerset
In England any side extension over one storey, including a room built over a side garage, needs a householder planning application. The fee is £548 from 1 April 2026 and councils aim to decide within 8 weeks.
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.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Working in Somerset
Towns we cover in Somerset include Bath, Weston-super-Mare, Taunton, Yeovil, Bridgwater, Portishead, Frome, Burnham-on-Sea. 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.
What should I budget for an over-garage extension in Somerset?
Labour and material costs vary across the UK, so for Somerset we use our South West England factor (×1.02). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Somerset: £1,840 to £3,470 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £24,000 – £30,000 | £25,500 – £33,500 | £33,000 – £42,000 |
| Over a large single garage 16 m² | £29,000 – £36,000 | £34,000 – £44,500 | £44,000 – £55,500 |
| Over a double garage 24 m² | £44,000 – £54,000 | £51,000 – £66,500 | £66,000 – £83,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
How the project works
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about an over-garage extension in Somerset
Do I need building regulations approval in Somerset?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Somerset?
Yes, across the whole of Somerset. Site visits are free and there is no obligation.
Will my neighbours in Somerset be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Does building over a garage need planning permission?
In England and the rest of the UK, adding a storey over a side garage almost always needs a planning application, because two-storey side extensions are outside permitted development.
How much does a room over a garage cost?
Our guide range is about £1,840 to £3,470 per m² including VAT. A single-garage room of about 12 m² usually costs £25,500 to £33,500 at standard spec, more if the garage needs rebuilding.
Book a free site visit in Somerset
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.