Planning permission in Hounslow
Constraints: planning.data.gov.uk (ingested 2026-08-01) · Prices: HM Land Registry UK House Price Index, December 2025 · 156 sales in December 2025 · Open Government Licence
Planning in Hounslow — the detail
Hounslow is a west-London borough of two halves: the heritage-rich east — Chiswick, Brentford and Isleworth — and the more suburban west out towards Heathrow. Its conservation areas are concentrated in that eastern belt, among them Bedford Park (the pioneering garden suburb, shared with Ealing), Chiswick House, Old Chiswick, Strand on the Green, Turnham Green, Gunnersbury Park, Osterley Park and the Isleworth Riverside, where design control is exacting.
Hounslow applies Article 4 directions in its most sensitive conservation areas — notably Bedford Park and Gunnersbury Park — removing permitted development rights so that even minor external changes need a planning application. The borough also made an HMO Article 4 direction (2022) that applies across most of the borough, removing the right to convert a house to a small HMO. Householder schemes are guided by the council's Residential Extension Guidelines SPD, which gives extra detail for heritage assets.
Outside the conservation areas, much of the borough's Victorian and interwar stock keeps permitted development rights for rear extensions, side extensions and loft conversions. The address-level check is what separates a permitted-development project from a full application in one of the protected areas — and confirms whether the HMO direction bites.
Policy detail lives in the Hounslow local plan and applications are submitted via the Hounslow planning portal.
Conservation areas in Hounslow
Real · planning.data.gov.ukEvery designated conservation area in Hounslow from the official dataset — inside one, permitted development narrows and design scrutiny rises.
- Bedfont Green
- Bedford Park
- Bedford Park (article 4)
- Chiswick High Road
- Chiswick House
- Cranford Park
- Cranford Village
- Feltham Town Centre
- Glebe Estate
- Grand Union Canal & Boston Manor
- Grand Union Canal and Boston Manor
- Grove Park
- Gunnersbury Park
- Gunnersbury Park (article 4)
- Hanworth Park
- Heston Village
- Hounslow Cavalry Barracks
- Isleworth Riverside
- Kew Bridge
- Old Chiswick
- Osterley Park
- Spring Grove
- St Dunstan's
- St Paul's Brentford
- St Paul's Church
- St Paul's, Brentford
- St Stephen's
- Stamford Brook
- Strand on the Green
- The Butts
- Thorney Hedge
- Turnham Green
- Wellesley Road
- Woodlands Grove
Source: planning.data.gov.uk · Open Government Licence. Boundaries are checked at address level by the area report.
Article 4 directions in Hounslow
Real · planning.data.gov.ukNo householder Article 4 geometry for Hounslow appears in the national planning.data.gov.uk dataset, but the borough operates significant directions: householder Article 4 directions in conservation areas such as Bedford Park and Gunnersbury Park (removing permitted development so even minor external changes need permission), and an HMO Article 4 direction (made 2022) applying across most of the borough. The Residential Extension Guidelines SPD sets householder design expectations. Check the council's Article 4 pages for the position at a specific address.
Source: planning.data.gov.uk · Open Government Licence · 2 directions recorded. Checked at address level by the area report.
Key Hounslow planning figures
| Conservation areas | 34 |
| Article 4 directions | 2 |
| Householder applications granted | 74.7% (526 of 704) |
| London average grant rate | 85.6% |
| Rank for lowest grant rate | 2 of 33 |
| Average house price | £519,960 |
| Annual price change | -1.0% |
Conservation areas and Article 4 directions: planning.data.gov.uk, ingested 2026-08-01 · Householder approval rates: MHCLG district planning application statistics (PS2), 2025 Q2 to 2026 Q1 · House prices: HM Land Registry UK House Price Index, December 2025 · Open Government Licence. Figures are as published on those dates; a designation missing from the national dataset is a gap in the dataset, not proof it does not exist.
What gets built in Hounslow
Chiswick and Isleworth terraces extend under PD outside the conservation areas; Bedford Park and the heritage areas need a full application.
Rear extension in Hounslow →A staple on the Chiswick and Brentford terraces; Bedford Park and the heritage areas need a full application.
Side return extension in Hounslow →Common on the Chiswick and Isleworth stock; Bedford Park and the heritage areas decide dormer form via a full application.
Loft conversion in Hounslow →More common in Chiswick's higher-value streets; a full application with structural and, near the river, flood-risk evidence is expected, to the Residential Extension Guidelines SPD.
Basement extension in Hounslow →Workable under PD on many plots; Bedford Park and the conservation areas can remove outbuilding rights — check the address.
Garden room in Hounslow →Hounslow postcode by postcode
W4 is Chiswick — Bedford Park (often called the world's first garden suburb, with an Article 4 direction), Chiswick House, Old Chi…
W4 planning report →TW8 is Brentford — the St Paul's Brentford conservation area, the Grand Union Canal and Boston Manor, and Kew Bridge. Riverside an…
TW8 planning report →TW7 covers Isleworth — the Isleworth Riverside and Spring Grove conservation areas and Osterley Park's edge. Period stock supports…
TW7 planning report →TW3 is central Hounslow — the Cavalry Barracks conservation area and the suburban stock around the town centre. Much of it keeps p…
TW3 planning report →TW13 is Feltham — the Feltham Town Centre and Bedfont Green conservation areas and the western suburbs near Heathrow. Conservation…
TW13 planning report →TW4 is Hounslow West and the Heston fringe — suburban stock away from the Chiswick heritage belt. Outside conservation areas, rear…
TW4 planning report →TW5 covers Heston and Cranford in Hounslow — interwar and later suburban housing near the A4 corridor. Conservation coverage is li…
TW5 planning report →TW14 covers Feltham and Bedfont in Hounslow (with a Hillingdon edge). Suburban and estate stock predominates; outside conservation…
TW14 planning report →Hounslow planning, asked straight
Is my Hounslow home in a conservation area?
What makes building in Bedford Park so controlled?
Do I need planning permission to create an HMO in Hounslow?
Do I need planning permission for a rear extension or loft in Hounslow?
How do I check constraints for a Hounslow address?
Related reading
Designated land edits the rulebook — here's the exact redline.
Read the guide →The designation nobody's heard of until it refuses their extension.
Read the guide →Four roof forms, four budgets — and one big conservation premium.
Read the guide →What applies at your address?
Borough-level rules only narrow it down. Enter a Hounslow postcode for the live constraint check — conservation area, Article 4 and sold-price comparables, cited to source.
Need it in writing for one address? A planning permission report for a Hounslow property — from £59, or surveyor-reviewed from £295.
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