Extensions over a garage in Hurstpierpoint

Useful details for planning an extension over a garage in Hurstpierpoint.

Postcode districts: BN6 and BN45
County / area: West 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: Burgess Hill (2.7 miles), Haywards Heath (5.5 miles), Portslade (6.5 miles)
Distance to Crawley: about 12.4 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 Hurstpierpoint we also work in Burgess Hill, Haywards Heath and Portslade, and across the rest of West Sussex. Postcode districts in and near Hurstpierpoint: BN6 and BN45.

What it costs in Hurstpierpoint

A guide price for Hurstpierpoint: around £34,500–£50,500 for 3 m × 6 m of new first-floor space (18 m²). That works out at £1,930–£2,800 per m² of new floor space, including VAT at 20%. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

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 Hurstpierpoint

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 Hurstpierpoint 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.

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 Hurstpierpoint we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Hurstpierpoint.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
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 Hurstpierpoint

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

Hurstpierpoint 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 Hurstpierpoint?

Our guide for South East England, which covers Hurstpierpoint, 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.

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.

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.

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.

Nearby

Other towns near Hurstpierpoint:

Other extensions in Hurstpierpoint

All two-storey extension services in Hurstpierpoint · Extensions over a garage across West Sussex

The quickest next step is a visit. We'll look at your house in Hurstpierpoint and give you an honest view of the options.