Extensions over a garage in Soho

Before you start in Soho, here's what applies.

Postcode districts: W1, W1B, W1C, W1D, W1F, W1G and nearby districts
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: St James's (0.5 miles), Holborn (0.7 miles), Westminster (1.2 miles)
First visit: Free, no obligation

About an extension over a garage

An extension over a garage suits you if you have an attached single garage beside the house and need an extra bedroom or a larger main bedroom with an en-suite. You get an inspection of the garage structure, a design that matches the house, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.

We cover Soho (W1, W1B, W1C, W1D, W1F, W1G and nearby districts) and the places around it, including St James's (0.5 miles), Holborn (0.7 miles) and Westminster.

What it costs in Soho

In London, which includes Soho, we'd expect an extension over a garage to cost around £38,000–£55,000 for 3 m × 6 m of new first-floor space (18 m²), or £2,100–£3,060 per m² including VAT. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 Soho

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 Soho homes

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.

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 Soho, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Soho.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about extensions over a garage in Soho

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 Soho?

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.

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

Our guide for London, which covers Soho, 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.

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.

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.

Nearby

The same service in neighbouring towns:

Other extensions in Soho

All two-storey extension services in Soho · Extensions over a garage across Greater London

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