Rear extension in Ealing
Do you need planning permission for a rear extension in Ealing?
Outside the conservation areas, much of Ealing's Victorian and Edwardian terrace stock keeps permitted development rights for a single-storey rear extension within the limits, or larger via prior approval. Inside a conservation area it is a full application to the standards in SPD 4 (Residential Extensions). Check the address first.
Long Victorian and Edwardian terraces in Hanwell, West Ealing and Acton extend routinely; conservation areas need a full application to SPD 4.
Long terrace runs in Hanwell, West Ealing, Acton and Northfields extend constantly, with a deep local precedent base for sensibly scaled rear additions. The conservation and garden-suburb set pieces — where design control on rooflines, materials and frontages is exacting — are a different environment: planning permission is needed for essentially all residential extensions there. Ealing's headline Article 4 change in October 2024 is about small HMO conversions, not ordinary rear extensions, though some conservation areas carry further householder restrictions.
What actually applies in Ealing
Conservation areas in Ealing
Real · planning.data.gov.ukEvery designated conservation area in Ealing from the official dataset — inside one, permitted development narrows and design scrutiny rises.
- Acton Green
- Acton Park
- Acton Town Centre
- Bedford Park
- Brentham Garden Estate
- Brunswick
- Canalside, northeast part
- Canalside, northwest part
- Canalside, southeast part
- Canalside, southwest part
- Churchfields
- Creffield
- Cuckoo Estate
- Ealing Common
- Ealing Cricket Ground
- Ealing Green
- Ealing Town Centre
- Grange and White Ledges
- Hanger Hill Garden Estate
- Hanger Hill, Haymills Estate
- Hanwell Cemeteries
- Hanwell Clock Tower
- Hanwell Village Green
- Haven Green
- Mill Hill Park
- Montpelier Park
- Mount Park
- Northolt Village Green
- Norwood Green
- Old Oak Lane
- St Mark's Church and Canal
- St Stephen's
Source: planning.data.gov.uk · Open Government Licence. Boundaries are checked at address level by the area report.
Article 4 directions in Ealing
Real · planning.data.gov.ukEaling's Article 4 directions aren't all in the national planning.data.gov.uk geometry, but the borough operates significant ones: directions made in October 2024 remove the permitted development right to convert a house (C3) into a small HMO (C4) — so an HMO conversion needs planning permission — and six conservation areas carry further Article 4 restrictions on householder permitted development. Check the council's Article 4 pages for the position at a specific address.
Source: planning.data.gov.uk · Open Government Licence · 1 directions recorded. Checked at address level by the area report.
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 Ealing, 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 Ealing?
| 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 Ealing
Do not confuse the borough-wide small-HMO conversion direction with a blanket ban on householder permitted development — they are different controls. Conservation-area streets still need a full application and SPD 4 detailing; daylight and party wall issues remain the routine hold-ups on unconstrained terraces.
Postcode districts in Ealing
W5 is the heart of the 'Queen of the Suburbs' — the Ealing Common, Ealing Green, Mount Park and Creffield conservation areas, the Hanger Hill Garden Estate and the pioneering Brentham Garden Estate at Pitshanger.
W5 — Ealing & Pitshanger →W13 runs from West Ealing to Northfields, taking in the St Stephen's and Montpelier Park conservation areas.
W13 — West Ealing & Northfields →W7 is Hanwell — the Hanwell Village Green, Hanwell Clock Tower and St Mark's Church and Canal conservation areas, with the Cuckoo Estate's planned cottages nearby.
W7 — Hanwell →W3 covers Acton — the Acton Park, Acton Green and Mill Hill Park conservation areas, with the Ealing side of Bedford Park, often called the world's first garden suburb.
W3 — Acton →UB2 reaches Southall and the Norwood Green conservation area, with its village green and the Grand Union Canal nearby.
UB2 — Southall & Norwood Green →UB1 is Southall in Ealing — dense terraces and mixed tenure with an Hillingdon edge.
UB1 — Southall →UB5 is Northolt on the Ealing–Harrow edge.
UB5 — Northolt →UB6 covers Greenford in Ealing (with a Harrow edge) — interwar and later suburban housing with industrial-edge pockets.
UB6 — Greenford →Rear extension in Ealing, asked straight
Do I need planning permission for a rear extension in Ealing?
How much does a rear extension cost in Ealing?
Does the 2024 small-HMO conversion direction affect my rear extension?
What is SPD 4?
Do I need a party wall agreement?
What applies at your address?
Borough-level rules only narrow it down. Enter a Ealing 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 Ealing
A rear extension is a design-and-consent job first: someone has to draw it and take it through Ealing'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.