Hackney · Greater London

Extensions over a garage in Hackney

If you live in Hackney and need more room without moving, an extension over a garage is worth a serious look. We handle the drawings, approvals, structure and build.

What we'd confirm first for a project in Hackney.

Postcode districts
E5, E8 and E9
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
Bethnal Green (1.3 miles), Canonbury (1.5 miles), Stamford Hill (1.8 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 postcode districts E5, E8 and E9 in and around Hackney, along with neighbouring Bethnal Green, Canonbury and Stamford Hill.

What it costs in Hackney

Our guide for London is £2,100–£3,060 per m² including VAT. On a project with 3 m × 6 m of new first-floor space (18 m²), that puts an extension over a garage in Hackney at roughly £38,000–£55,000. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

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 Hackney

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 Hackney 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.

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. Measure and listen

    A visit to Hackney to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Price it properly

    Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.

  4. Build it

    The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about extensions over a garage in Hackney

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 planning permission for an extension over a garage in Hackney?

Hackney 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.

Which postcodes do you cover around Hackney?

We cover Hackney (E5, E8 and E9) and nearby places including Bethnal Green, Canonbury and Stamford Hill, plus the rest of Greater London. The first site visit is free.

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.

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

Other towns near Hackney:

Other extensions in Hackney

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

Book a free site visit in Hackney and we'll tell you what's possible, what approvals you need and what the design stage would cost.

CallGuide price