Rear extension in Hackney
Do you need planning permission for a rear extension in Hackney?
Outside a conservation area, most Hackney houses keep their full permitted development rights: a single-storey rear extension up to 3m (attached) or 4m (detached) needs no application, and the larger 6m/8m 'larger home extension' route is available too via prior approval. Inside one of Hackney's conservation areas, that basic single-storey allowance usually survives, but two-storey rear extensions lose the permitted development route entirely and always need a full application there. Hackney's Article 4 directions aren't in the national planning.data.gov.uk dataset at all — a data gap, not confirmation none apply — so a lawful development certificate or a direct check with the council is the only way to be certain before you design.
London's most active rear-extension market; contemporary design with good brickwork is mainstream.
That contemporary confidence extends across the borough's terrace stock: exposed brick, generous glazing and flat-roofed additions are standard fare on Hackney's Victorian streets, and officers weigh design quality on its own terms rather than defaulting to a period-matching brief. The distinction that actually matters for feasibility isn't style, though — it's which side of a conservation-area boundary a postcode falls on, since that decides between prior approval for a larger scheme and a full application argued on materials and neighbour daylight. Even inside the conservation areas, well-detailed modern schemes have a genuine track record of approval, not just tolerance.
What actually applies in Hackney
Conservation areas in Hackney
Real · planning.data.gov.ukEvery designated conservation area in Hackney from the official dataset — inside one, permitted development narrows and design scrutiny rises.
- Albion Square
- Beck Road
- Broadway Market
- Brownswood
- Clapton Common
- Clapton Pond
- Clapton Square
- Clissold Park
- Dalston
- Dalston Lane (West)
- De Beauvoir
- Fremont and Warneford
- Graham Road and Mapledene
- Hackney Road
- Hackney Wick
- Hoxton Street
- Kingsland
- Lea Bridge
- Lordship Park
- Mare Street
- Newington Green (North)
- Northwold & Cazenove
- Pitfield Street
- Queensbridge Road
- Regent's Canal
- Regent's Canal - Central & South Hackney CAAC
- Regent's Canal - Kingsland CAAC
- Regent's Canal - Shoreditch CAAC
- Shacklewell Green
- South Shoreditch
- St Mark's
- Stoke Newington
- Stoke Newington Reservoirs, Filter Beds and New River
- Sun Street
- Town Hall Square
- Underwood Street
- Victoria Park
- Well Street Conservation Area
Source: planning.data.gov.uk · Open Government Licence. Boundaries are checked at address level by the area report.
Article 4 directions in Hackney
Real · planning.data.gov.ukHackney's Article 4 directions haven't reached the national planning.data.gov.uk dataset yet — almost certainly a coverage gap, not an absence of directions. Hackney does use Article 4 powers; check the council's planning pages for the definitive schedules until the geometry lands.
Prices: HM Land Registry UK House Price Index, January 2026 · Open Government Licence.
The planning route — PD or permission?
Permitted development (GPDO Class A) covers single-storey rear extensions up to 3m beyond the original rear wall on attached houses and 4m on detached, with a maximum height of 4m. The 'larger home extension' route extends this to 6m/8m through prior approval with neighbour consultation — but that larger route is not available in conservation areas.
In conservation areas, the basic 3m/4m single-storey rear PD allowance usually survives — what conservation-area status removes is side extensions and two-storey rear extensions. An Article 4 direction can remove more, but Camden's directions in Hampstead and Belsize target front-and-side appearance (solar panels, window changes, boundary treatments), not the single-storey rear allowance. Flats have no PD rights at all. Two-storey rear extensions in conservation areas always need full permission.
Practical rule across London: check the address first. If a conservation area or Article 4 direction applies, budget for a full householder application decided on design, neighbour daylight (the 45-degree test) and materials.
Permitted development limits — rear extension
| Single-storey rear depth — attached house | 3m beyond the original rear wall |
| Single-storey rear depth — detached house | 4m beyond the original rear wall |
| Larger extension via prior approval | 6m attached / 8m detached — not in conservation areas |
| Maximum height (single storey) | 4m |
| Two-storey rear in a conservation area | Full planning permission required |
| Flats | No permitted development rights |
Limits summarise the General Permitted Development Order (Schedule 2, Part 1) as it applies in London. In Hackney, a conservation area, Article 4 direction or listed status changes the route — the panels above show what is designated, and the address check confirms what applies at your property.
How much does a rear extension cost in Hackney?
| Cost per m² (low — straightforward site) | £3,000 |
| Cost per m² (expected) | £3,800 |
| Cost per m² (high — conservation spec, hard access) | £4,600+ |
| Typical build cost (12–18m² single storey) | £36,000 – £83,000 |
| Professional fees, surveys, party wall (add) | 10–18% of build |
Indicative London ranges calibrated from real project data. Conservation-area specifications (matching stock brick, lime mortar, bespoke glazing) and restricted rear access are the two biggest cost drivers. VAT not included.
Realistic timeline
| Design and drawings | 4–8 weeks |
| Planning decision (full application) | 8–12 weeks (8-week statutory target) |
| Prior approval route, where available | 42 days |
| Party wall agreements | 4–10 weeks (parallel) |
| Build | 3–5 months |
What catches people out in Hackney
The recurring refusal pattern in Hackney is depth against daylight: extensions pushed to the maximum on a tight terraced plot routinely fall foul of the 45-degree test to a neighbour's windows, and overdevelopment of small rear gardens is one of the borough's most cited reasons for refusal. Don't assume your permitted development rights are intact just because a neighbour built recently — with Hackney's Article 4 position unconfirmed in the national dataset, a silently removed right is the other common trap.
Postcode districts in Hackney
E8's Victorian terraces around London Fields and Graham Road are among the most actively extended in London.
E8 — Hackney Central, Dalston & London Fields →E9 mixes Homerton's terraces with Hackney Wick's converted industrial stock on the Lea.
E9 — Homerton & Hackney Wick →E5's stock runs from Clapton Square's Georgian survivors to long Victorian runs towards the Lea marshes.
E5 — Clapton & Lea Bridge →N16's Church Street core and the streets around Clissold Park sit in conservation areas with active local scrutiny, while Stamford Hill's larger semi-detached stock sees frequent loft and rear conversions, often for big households.
N16 — Stoke Newington & Stamford Hill →Rear extension in Hackney, asked straight
Can I build a two-storey rear extension in Hackney under permitted development?
Can I extend a flat in Hackney?
How do I check if Article 4 affects my Hackney permitted development rights?
How much does a rear extension cost in Hackney?
What applies at your address?
Borough-level rules only narrow it down. Enter a Hackney postcode for the live constraint check — conservation area, Article 4 and sold-price comparables, cited to source.
Free, and it stays free — no account, no payment. The check reads official geometry at the property's own coordinates; listed status, lease terms and the state of the building all sit outside it.
Who to talk to about a rear extension in Hackney
A rear extension is a design-and-consent job first: someone has to draw it and take it through Hackney's planning route. The neighbour, condition and party wall side is separate work and a different profession — which is why there are two doors here, not one.
An extension is a design and consent job: the scheme, the planning application or prior approval, then the building-regs package.
- Residential design for extensions, lofts, basements and conversions
- Planning applications, pre-application advice and appeals
- Lawful development certificates
- Building-regulations and technical design drawings
- Conservation-area design and listed building consent applications
Excavating foundations within 3m of a neighbour is notifiable — the surveyor serves the party wall notices.
- Building surveys, RICS home surveys and defect diagnosis
- Party wall matters and awards
- Technical due diligence before a purchase
- Leasehold and major-works advisory (Section 20)
- Dilapidations and building pathology
Both practices are independent and separately regulated — Hampstead Chartered Surveyors & Building Consultancy is an RICS-regulated firm (Firm Reg. 923064); Hampstead Architecture and Planning are ARB-registered architects. We publish no fees for their work: each quotes directly for the job in front of them. Your enquiry goes to the practice you choose — we never pass your details to builders or other third parties.
Planning terms on this page
Conservation Area · Article 4 Direction · Permitted development · Full planning · Prior approval · Party wall · Designated land
Plain-English definitions · full planning glossary →
Planning Permission Checker provides planning and cost intelligence for early feasibility only. It is not legal, planning, valuation, architectural, structural, or surveying advice. All estimates are indicative and must be verified by qualified professionals before purchase, design, planning submission, or construction.
Cost estimates are indicative only — not a quotation. Final price depends on survey, specification, structure, access, party wall matters, VAT, professional fees, and contractor availability.
Planning outcomes are not guaranteed. Local planning authorities make final decisions.