Stratford · Greater London

Extensions over a garage in Stratford

Our extensions over a garage service in Stratford covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.

Quick reference for homeowners in Stratford.

Postcode districts
E15
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
West Ham (0.7 miles), Bow (0.9 miles), Canning Town (1.6 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 Stratford (E15) and the places around it, including West Ham (0.7 miles), Bow (0.9 miles) and Canning Town.

What it costs in Stratford

A guide price for Stratford: around £38,000–£55,000 for 3 m × 6 m of new first-floor space (18 m²). That works out at £2,100–£3,060 per m² of new floor space, including VAT at 20%. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

SpecPer m²3 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 Stratford

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 Stratford 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.

Checking the garage foundations

Garages are often built on shallow strip footings sized for a single-storey wall and a light roof. A trial hole shows their depth and condition, and the engineer decides whether they can carry two storeys or need underpinning or new foundations inside the garage.

How we'd run your project

  1. Understand the brief

    At your home in Stratford we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Design and approvals

    We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.

  3. Fixed price in writing

    With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.

  4. 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 Stratford

Who handles building regulations for a project in Stratford?

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 Stratford?

Our guide for London, which covers Stratford, 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.

Which postcodes do you cover around Stratford?

We cover Stratford (E15) and nearby places including West Ham, Bow and Canning Town, plus the rest of Greater London. The first site visit is free.

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.

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

Nearby towns we cover for extensions over a garage:

Other extensions in Stratford

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

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.

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