House Extensions Hackney
Single storey rear and double storey extensions in Hackney, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
GS Renovation builds extensions across Hackney, on the borough's period terraces near Broadway Market and London Fields and on ground-floor flats with garden rights. We handle foundations, steelwork, roofing and fit-out, and guide you through Hackney Council's planning rules from the first drawing.
In Hackney, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Hackney: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Hackney
Hackney range: choose above
Rear and side-return extensions in Hackney
The classic Hackney extension adds space to a Victorian terrace, either extending the rear or filling the side return to widen a narrow kitchen. We dig and lay the foundations, allowing for any trees or shallow drains common on these older plots, then form the walls and fit steel beams where the back of the house opens up. A well-detailed flat or pitched roof, with rooflights, keeps the new space bright and usable.
Whether your project is permitted development or needs a full planning application depends on the property. Many single-storey rear extensions in Hackney fall under permitted development, but flats, side extensions in conservation areas and larger double-storey schemes usually need permission from Hackney Council. We assess your specific address, coordinate the application with your architect where one is required, and give you the drawings and programme your party wall notices need (you serve them as building owner) before building work begins on your E8 or N16 home.
Housing in Hackney
The valuation list shows roughly 120,710 homes in Hackney, of which 35% are pre-1919, 8% interwar and 56% post-1945, split 83% flats to 17% houses. Where most homes are flats, a flat in Hackney has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.
What Hackney's extensions SPD means for a terrace rear extension
Hackney Council's residential extensions and alterations SPD was adopted in December 2025 and came into effect in January 2026. The figures here come from its consultation draft, so the adopted wording is checked before a design is fixed. The draft says single storey rear extensions to terrace houses should be no deeper than 3m from the rear elevation of the original dwelling. The words original dwelling matter: a conservatory or earlier extension added later does not move the starting line. On a Victorian terrace with a back addition, whether a wraparound is measured from the main rear wall or the end of the addition is a question for the adopted text and the case officer before the drawings go further.
Two more tests sit alongside it. The draft says any extension will need to retain at least 50% of the original rear garden, which on a short Hackney plot can bind before the depth does. It also applies a 45 degree rule, under which an extension should not exceed a line taken at 45 degrees from the centre of the nearest ground floor habitable room window of an adjoining building. We measure the neighbours' windows and the garden at the survey, and the architect draws the height and depth to both lines, so the planning drawings are not redrawn after the first officer comment. These tests guide planning applications; a house extending under permitted development is measured against the national limits instead.
Extending Hackney flats and conversions
Extending a warehouse conversion or new-build apartment is a different matter from extending a house. Structural change is limited, and any alteration to the building's fabric usually needs the freeholder's consent and coordination with the managing agent. Rather than a rear extension, projects here often mean reconfiguring the existing envelope, adding a mezzanine where the ceiling height allows, or enclosing a balcony, all within the building-management rules set out in your lease.
Where a genuine extension is possible, such as on the ground floor of a converted building with garden rights, we work through both Hackney Council's planning requirements and the terms of your lease. We build to the engineer's structural and drainage details, manage sound insulation between units, and sequence the work to minimise disruption to neighbours in your block across Dalston, Hoxton or Shoreditch while keeping the managing agent informed throughout.
Kitchen extensions in Hackney
83% of homes in Hackney are flats, and a flat has no householder permitted development, so a ground-floor flat's kitchen extension needs planning permission from Hackney Council and the freeholder's consent. Most kitchen extensions here are on the 17% of homes that are houses. The fit-out is priced on its own page, kitchen renovation in Hackney; the build figures are in the table above.
Double storey extensions in Hackney
Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Hackney often needs planning permission from Hackney Council. It is a job for the 17% of homes that are houses; a flat cannot add a storey this way. Hackney Council's conservation areas map page says there are now 35 conservation areas across the borough (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- Building control inspections at foundation, damp course and steel stages
- Drawings and the structural engineer's design coordinated for you
- Foundations, groundworks and steel frames
VOA Council Tax stock of properties, March 2025, for all 30 statistical areas in Hackney. Counts rounded by the VOA.
Why Choose GS Renovation in Hackney
Homeowners across Hackney choose GS Renovation because we understand both sides of the borough, the freehold terraces and the leasehold conversions. We tell you honestly whether your extension is permitted development or a planning matter, plan around party wall notices and any licence to alter, and deliver the groundwork, steel and finish as one project backed by our founder's 30+ years on the tools.
- Programme planned around party wall notice periods before excavation near a neighbour
- Fully insured, with cover in place on every site
- Insulation and thermal detailing to current regulations
Reviewed jobs near Hackney
1 MyBuilder review from Stoke Newington, with each customer's own job title:
- Install new dishwasher, Stoke Newington, 24 May 2021 (5 out of 5)
Read all 31 on our reviews page.
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
Saaid is the best craftsman I have worked with. He knows what he is doing from the very beginning. He has a great knowledge of construction…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
FAQ
Frequently Asked Questions about House Extensions Hackney
What does the house extensions quotation for a Hackney home cover?
The house extensions quotation for a Hackney home covers the whole job through to sign-off, typically within £2,000 to £2,800 per m² for a rear extension (indicative). It lists the structural work, the following trades, a Hackney Council building control inspection of the foundations before concrete is poured, and the making good at E8, with the engineer's design shown as its own line. GS Renovation issues it in writing so you have something to hold us to.
Does my Hackney extension need planning permission or is it permitted development?
Many single-storey rear extensions on Hackney houses are permitted development, but flats and conversions have no such rights, and side or larger extensions in the borough's conservation areas usually need consent. We check your exact address and the council's records, then either confirm permitted development or coordinate the planning application to Hackney Council with the architect who draws it.
Will a tree near my Hackney extension affect the build?
It can decide the foundation depth. Roots draw water from the ground, so building control may require the trench to go deeper near a tree, set from its species and distance. The depth is confirmed when the excavation is inspected. Shallow drains on older Hackney plots are located at the same time, since a deeper trench can cut across one.
Does a side-return extension to a Hackney house involve next door?
Usually, if the new wall or footings come close to the house next door. Under the Party Wall etc. Act 1996, a trench deeper than their footing and within 3 metres of their house calls for one month's notice; seating steel in the shared wall calls for two. Should they dissent, a surveyor's award follows, so the notices go out early.
When does Hackney building control inspect an extension?
At each stage that will later be covered. The foundation trench is inspected before concrete, then the drainage is tested, then the steel and bearings, the insulation before it is boarded, and finally the completed work. Missing a stage can mean opening it up again, so each visit is booked as that stage finishes.
Should a Hackney rear extension have a flat or pitched roof?
That depends on the height below the upstairs windows of the house. A pitched roof against the back wall needs enough room for its slope and insulation beneath the first-floor sills. A flat roof sits lower and can take rooflights or a lantern. Either way Part L sets the insulation depth, which drives the finished roof height.
Does a public sewer behind a Hackney house affect how an extension is approved?
Yes. A building notice cannot be used with Hackney Building Control where the proposal is within 3 metres of or over a public sewer, and a full plans application is required instead. Behind a terrace the drain serving several houses can run under the gardens, and an extension footprint can easily land within that distance. A drain survey before the drawings are finished shows where the pipe runs, and whether the water company's consent to build near it is needed as well.
Can a Hackney house in the Shacklewell Green Article 4 area extend under permitted development?
Not on the streets the direction lists. Hackney Council's Article 4 Direction over part of the Shacklewell Green Conservation Area was made on 30 August 2018 and has been effective from 22 October 2019. It removes permitted development rights under Schedule 2, Part 1, Classes A to H, which is the part covering extensions and other works within the curtilage of a house. Where permitted development does apply, a lawful development certificate confirms it, and Hackney says it will issue one within 8 weeks.
Will a Hackney extension be charged the Community Infrastructure Levy?
For a typical house extension, probably not. Hackney Council says development of less than 100 square metres will not normally be assessed as liable for CIL unless it is a whole dwelling, in which case the levy is payable. Where a larger extension is liable, one built by a self builder can claim exemption, but the claim for relief must be made and accepted before development commences. A claim made after the footings are dug is too late, so it goes in with the approved drawings.
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