Ealing's own guidance says 3 metres in one document and 3.5 in another. We tell you which one applies to your house, whether your street has lost its permitted development right, and what the drawings will cost.
Photo: sludgegulper, BY-SA 2.0
There is no single Ealing number, and that is the first thing to know. The council's Supplementary Planning Document 4 on residential extensions says three metres of depth is normally appropriate, and allows more depending on the size of the house, the neighbour's position and the roof pitch. The Housing Design Guidance of November 2022 is more generous: it says rear extensions of 3.5 metres are likely to be acceptable, and that anything deeper needs a sound design justification showing how the massing protects the neighbours.
Both documents sit under the same test. The 2022 guidance asks extensions to keep within the 25 and 45 degree lines used to judge overshadowing of the next-door property. So the depth you can really reach is set by where the neighbour's nearest window is, not by a table. A house with a neighbour who has already extended can often go further than one whose neighbour has an untouched kitchen window beside the boundary.
SPD 4 adds design points that case officers do read. A rectangular house should not usually be extended across its full width or wrapped round the side. An L-shaped house can be infilled, but the new wall should step back about 500 millimetres from the end of the projecting wing. Roofs are normally pitched to match the main house, with flat roofs accepted only where the character of the house allows and finished with parapets.
Five Ealing rules shape a rear extension drawing before the first line is drawn.
| Check | What Ealing says | Where |
|---|---|---|
| Normal depth | 3 metres is normally appropriate; more depends on the house and neighbour | SPD 4 residential extensions |
| Likely depth | 3.5 metres likely to be acceptable; deeper needs a design justification | Housing Design Guidance, Nov 2022 |
| Massing | Keep within the 25 and 45 degree rule to avoid overshadowing | Housing Design Guidance, Nov 2022 |
| Full-width extension | Not usually appropriate on a rectangular house | SPD 4 residential extensions |
| Invalid application | Returned if the fault is not fixed within 28 days | Ealing validation page |
Ealing Council documents opened on 25 October 2026.
The fee includes our measured visit. The bracketed figure applies if you already have measured drawings.
Ealing's Article 4 page lists the conservation areas where the council has removed permitted development. In Bedford Park the direction covers the enlargement, improvement or other alteration of a dwelling house. Brentham Garden Estate and Hanger Hill Garden Estate use the same wording and add windows, doors, roof materials and chimneys. At Hanger Hill (Haymills) Estate the direction covers outbuildings to the side or rear, and the Grove in Ealing Town Centre covers enlargement as well.
For example, a pair of Edwardian houses in Bedford Park cannot rely on the 3 metre right at all: even a modest kitchen extension needs an application. A similar pair a few streets over, outside every direction, can often be proved lawful with a certificate and no full application. The first thing we do on any Ealing address is read the direction that applies to it.
If your house is outside those areas and your scheme fits the Class A limits, a lawful development certificate settles the point on paper before the builder starts. If it is deeper than the limit but within Ealing's 3.5 metre guidance, a householder application is the usual route.
Every figure is linked to the page or document we read.
Ealing SPD 4 says three metres depth is normally appropriate for rear extensions, and that an L-shaped infill should be set back around 500 millimetres from the end of the wing.
Source: Ealing Council, SPD 4 Residential ExtensionsEaling's Housing Design Guidance of November 2022 says rear extensions of 3.5 metres in depth are likely to be acceptable.
Source: Ealing Council, Housing Design Guidance, November 2022The same guidance asks extensions to adhere to the 25 and 45 degree rule to avoid overshadowing neighbouring properties.
Source: Ealing Council, Housing Design Guidance, November 2022Ealing has Article 4 directions in 6 conservation areas, including Bedford Park, Brentham Garden Estate, Hanger Hill Garden Estate, Hanger Hill (Haymills) Estate, Churchfields and the Grove.
Source: Ealing Council, Article 4 DirectionsEaling aims to validate applications within 5 to 10 working days and returns an invalid one if nothing is heard within 28 days.
Source: Ealing Council, ValidationEaling decided 424 householder applications between July 2025 and June 2026, prior approvals excluded, and 407 of them were decided within 8 weeks.
Source: MHCLG, Planning application statistics PS2, July 2025 to June 2026Permitted development allows a single-storey rear extension up to 4 metres on a detached house or 3 metres on any other house.
Source: legislation.gov.uk, GPDO 2015, Schedule 2, Part 1, Class AClass A is lost if the extension and other buildings would cover more than 50% of the garden, excluding the original house.
Source: legislation.gov.uk, GPDO 2015, Schedule 2, Part 1, Class ATell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Neither is a hard limit. SPD 4 calls 3 metres normally appropriate and the 2022 Housing Design Guidance says 3.5 metres is likely to be acceptable. Past either figure you need a design justification, and permitted development sets its own cap of 3 metres on most houses and 4 on a detached one.
Yes. The Article 4 directions there withdraw the right to enlarge or alter a dwelling house, so even a small single-storey extension needs an application. Ealing's Article 4 page says that does not mean it will be refused, only that the council controls it.
SPD 4 says a rectangular house should not usually be extended across its full width or wrapped around the back and side. An L-shaped house may be infilled if the new wall stays back about 500 millimetres from the end of the wing.
Ealing aims to validate within 5 to 10 working days and writes to say what is missing. If you do not respond within 28 days the application is returned and an administration fee is charged. We check the list before we submit so that does not happen.
£765 inc survey (£565 if you supply measured drawings). That covers the measured survey, the drawings and the submission, with free revisions until the council decides. The council's own application fee is separate and goes to the council.
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