Extensions over a garage across Nailsea
Thinking about an over-garage extension for your Nailsea home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in NailseaFrom £24,000 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsBS48
How much does an over-garage extension cost in Nailsea?
Labour and material costs vary across the UK, so for Nailsea we use our South West England factor (×1.02). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Nailsea: £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.
Covering Nailsea
Postcode districts we cover around Nailsea include BS48. Nearby, we also take on projects in Portishead (3 miles), Clevedon (4 miles), Weston-super-Mare (11 miles), Keynsham (11 miles).
Kingswood, in Gloucestershire, is roughly 11 miles from Nailsea and also on our list. 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 Nailsea
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
What we take care of
- Structural survey of garage walls and foundations
- New floor structure, walls and roof
- Design and householder planning application
- Opening into the existing first floor
Fitting the new room to the existing landing is the planning puzzle inside the house. We design the connection first, then the roof, so the extension does not end up with awkward steps or a corridor through a bedroom.
What happens next
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 Nailsea home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about an over-garage extension in Nailsea
Who do I contract with for an over-garage extension in Nailsea?
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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Nailsea, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Nailsea?
Yes. We cover Nailsea and the surrounding parts of Somerset. Site visits are free and there is no obligation.
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.
Can I keep using the garage during the build?
Usually not for parking. The garage roof is removed and the space below is used for access and props for part of the build.
Book a free site visit in Nailsea
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.