Extensions over a garage in Gipsy Hill
Thinking about an extension over a garage in Gipsy Hill? We design it, take it through the approvals it needs and build it, with one team responsible from the first visit to the final certificate.
Before you start in Gipsy Hill, here's what applies.
- Postcode districts
- SE21 and SE27
- County / area
- Greater London, England
- Price region
- London
- Guide price
- £38,000–£55,000 (£2,100–£3,060 per m²)
- Approval route
- Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
- Nearest towns
- Crystal Palace (0.8 miles), Upper Norwood (0.9 miles), Norbury (1.3 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 Gipsy Hill (SE21 and SE27) and the places around it, including Crystal Palace (0.8 miles), Upper Norwood (0.9 miles) and Norbury.
What it costs in Gipsy Hill
Using our London rates, an extension over a garage with 3 m × 6 m of new first-floor space (18 m²) comes to about £38,000–£55,000, including VAT. Bigger or more glazed designs cost more per m². Keep a contingency of around 10% for things nobody can see until the ground is opened up.
| Spec | Per m² | 3 m × 6 m of new first-floor space (18 m²) |
|---|---|---|
| Essential | £1,930–£2,820 per m² | £35,000–£50,500 |
| Standard | £2,100–£3,060 per m² | £38,000–£55,000 |
| Premium | £2,520–£3,670 per m² | £45,500–£66,000 |
Planning and building regulations in Gipsy Hill
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 Gipsy Hill homes
Garage walls and the door opening
Garage walls are often a single skin of brick or block with piers, and the wide door opening needs a beam over it. Many over-garage extensions need new inner walls or a steel frame to carry the floor and to insulate properly, which we confirm before the design is fixed.
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.
How we'd run your project
Start at your house
We come to your home in Gipsy Hill, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about extensions over a garage in Gipsy Hill
How much does an extension over a garage cost in Gipsy Hill?
Our guide for London, which covers Gipsy Hill, is £2,100–£3,060 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £38,000–£55,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
How long does an extension over a garage take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
Who handles building regulations for a project in Gipsy Hill?
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 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.
Can my garage take a room on top?
Sometimes, but it needs checking. Many garages are built on shallow footings with thin walls, designed only for a single storey. We dig a trial hole and inspect the walls, and the structural engineer decides whether to reuse them, strengthen them, underpin the footings or build new foundations inside the garage.
Nearby
Other towns near Gipsy Hill:
Other extensions in Gipsy Hill
- Rear
- Side
- Wraparound
- Part two-storey
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Gipsy Hill · Extensions over a garage across Greater London
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Gipsy Hill.