Architects in W4
Chiswick, Grove Park, Strand on the Green and Turnham Green. Victorian and Edwardian houses, several conservation areas, and the riverside.
RIBA Chartered Practice · ARB-registered architects · Extensions, lofts and planning drawings
Planning authority
Which council decides in W4?
W4 is split between 2 councils, so the council that decides your application depends on your street. 1,048 postcodes, 4.9 miles from our studio.
By postcode sector
| Sector | Postcodes | Council |
|---|---|---|
| W4 1 | 199 | Ealing (mostly; some streets in another council) |
| W4 2 | 223 | Hounslow (mostly; some streets in another council) |
| W4 3 | 250 | Hounslow |
| W4 4 | 139 | Hounslow |
| W4 5 | 214 | Ealing (mostly; some streets in another council) |
| W4 9 | 23 | Hounslow |
Postcode checker
Check your exact postcode
Type any postcode in the 33 London boroughs we cover. We'll tell you which council handles planning there and show you the local planning points.
Local planning points
If your home is in Hounslow
Single-storey rear extensions are limited to 3.05m deep on terraced houses, 3.65m on semi-detached and 4.25m on detached houses (Residential Extension Guidelines, May 2024).
SourceFull-width box dormers are normally refused; dormers must be set in from the ridge, eaves and sides, by at least 1m on larger houses.
SourceA borough-wide Article 4 direction has required planning permission for small HMOs since 4 September 2023.
Source
Local planning points
If your home is in Ealing
Ealing's residential extensions guidance (SPD 4) uses a general limit of 3m deep and 3m high for single-storey rear extensions, with more possible on detached houses or where neighbours are well separated. The guidance is old, so how much weight it now carries should be checked case by case.
SourceConverting a house to a small HMO needs planning permission across the borough. An Article 4 direction has applied in Perivale since 30 October 2024 and in the rest of the borough since 14 November 2025.
SourceA new Ealing Local Plan is at examination; the inspectors issued their main-modifications letter in June 2026.
Source
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