Extensions over a garage in Oxted

What we'd confirm first for a project in Oxted.

Postcode districts: RH8 and RH9
County / area: Surrey, England
Price region: South East England
Guide price: £34,500–£50,500 (£1,930–£2,800 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Caterham (3.6 miles), Biggin Hill (4.3 miles), Sanderstead (6.3 miles)
Distance to Woking: about 24.3 miles
First visit: Free, no obligation

About an extension over a garage

An extension over a garage is a new first-floor room built on top of an existing attached garage, usually a bedroom, en-suite or study. It uses a footprint you already have, so it adds floor space without taking any garden. The garage walls and foundations often need strengthening or replacing to carry the new floor.

We cover Oxted (RH8 and RH9) and the places around it, including Caterham (3.6 miles), Biggin Hill (4.3 miles) and Sanderstead.

What it costs in Oxted

Using our South East England rates, an extension over a garage with 3 m × 6 m of new first-floor space (18 m²) comes to about £34,500–£50,500, including VAT. Bigger or more glazed designs cost more per m². The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

Spec	Per m²	3 m × 6 m of new first-floor space (18 m²)
Essential	£1,770–£2,580 per m²	£32,000–£46,500
Standard	£1,930–£2,800 per m²	£34,500–£50,500
Premium	£2,310–£3,370 per m²	£41,500–£60,500

Planning and building regulations in Oxted

In England, most garages sit beside the house, so building over one makes a two-storey extension beyond a side wall, which always needs planning permission. If the garage is at the rear, the 3 m and 7 m rules for two-storey rear extensions apply, measured from the original house. A householder application costs £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Oxted homes

Floor levels and headroom

Garage floors are often lower than the house, and the new first floor may not line up with the existing landing. We set the floor level to avoid awkward steps upstairs, while keeping enough headroom in the garage below for a car or storage.

Matching the house

A room over a garage usually sits beside the front of the house in full view, so roof form, ridge height, windows and brick matter. Setting the front wall and ridge back slightly from the main house usually helps it look as if it belongs.

How we'd run your project

Understand the brief
At your home in Oxted we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about extensions over a garage in Oxted

Who handles building regulations for a project in Oxted?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Do I need planning permission for an extension over a garage in Oxted?

Oxted is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does an extension over a garage cost in Oxted?

Our guide for South East England, which covers Oxted, is £1,930–£2,800 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £34,500–£50,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Can I add an en-suite above the garage?

Yes, and it is a common choice for a main bedroom. The en-suite needs an extract fan under Part F, a route for the soil pipe down to the drains and enough fall for the waste, which can be harder over a garage. We plan the pipe route through the garage or an outside wall early.

Do I need to convert the garage as well?

No. You can keep the garage for parking or storage and build only the room above, as long as the floor between them and any door into the house meet fire separation rules. Converting the garage at the same time is often good value, because the walls and foundations may be upgraded anyway.

Nearby

Nearby towns we cover for extensions over a garage:

Other extensions in Oxted

All two-storey extension services in Oxted · Extensions over a garage across Surrey

Tell us about your house in Oxted and we'll call you back to arrange a free, no-obligation visit.