Extensions over a garage in Hastings
Thinking about an extension over a garage in Hastings? 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 Hastings, here's what applies.
- Postcode districts
- TN31, TN34, TN35 and TN36
- County / area
- East Sussex, 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
- St Leonards-on-Sea (1.5 miles), Bexhill-on-Sea (4.8 miles), Hailsham (14.1 miles)
- Distance to Brighton
- about 31.5 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.
Around Hastings we also work in St Leonards-on-Sea, Bexhill-on-Sea and Hailsham, and across the rest of East Sussex. Postcode districts in and near Hastings: TN31, TN34, TN35 and TN36.
What it costs in Hastings
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. Professional fees for drawings and the structural engineer are listed separately on our prices page.
| 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 Hastings
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 Hastings 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
Visit and first ideas
One of our team visits your house in Hastings, checks the walls, roof and drains, and sketches out options with you.
Get it approved
Once you're happy with the design we submit it to the council for Hastings and deal with any questions from the planning officer.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.
Questions about extensions over a garage in Hastings
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.
Which postcodes do you cover around Hastings?
We cover Hastings (TN31, TN34, TN35 and TN36) and nearby places including St Leonards-on-Sea, Bexhill-on-Sea and Hailsham, plus the rest of East Sussex. The first site visit is free.
Do I need planning permission for an extension over a garage in Hastings?
Hastings 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 do I get into a room over the garage?
Usually through a new opening off the existing landing or a bedroom, so the stairs stay where they are. If the floor levels do not match, a step or two may be needed inside the new room. Where a landing opening is not practical, a new stair from a converted garage is an option.
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
We also cover places near Hastings, including:
Other extensions in Hastings
- Rear
- Side
- Wraparound
- Part two-storey
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Hastings · Extensions over a garage across East Sussex
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Hastings.