20 Alwyn Avenue Chiswick London W4 4PB
Proposal
Certificate of Lawfulness for erection of a rear roof extension to main roof and outrigger with juliette balcony and three roof windows to front elevation
- Received
- 21 December 2017
- Decided
- 9 March 2018 · Refused (Full Planning Permission Required)
- Decision level
- Delegated (officer decision)
- Council
- London Borough of Hounslow
- Ward
- Turnham Green (Pre May 2022)
Boundary © HM Land Registry, © Ordnance Survey · details
This information is subject to Crown copyright and database rights 2026 and is reproduced with the permission of HM Land Registry. The polygons (including the associated geometry, namely x, y co-ordinates) are subject to Crown copyright and database rights 2026 Ordnance Survey AC0000851063. Conditions of use.
- ReceivedSubmitted21 Dec
- ValidatedValidated12 Jan
- Consult.Consultation
- TargetTarget Date
- DecidedDecided9 Mar
Decided in 56 days (council typically 56)
This is an outline application for an extension at 20 ALWYN AVENUE CHISWICK LONDON W4 4PB. Hounslow has handled 1,065 applications of this type and approves 85% of them, typically deciding them in 48 days. This one was decided in 78 days, 4 weeks longer than Hounslow's median. The site is in the Turnham Green conservation area. There have been 2 other applications at this address. We hold 6,560 applications in total for the W4 postcode area.
Application Details
Applicant & Agent
Planning Application Dates
Planning Decision
Publicity
Appeal
Additional Information
Source: Hounslow
Contains public sector information from the Planning London Datahub, licensed under the Open Government Licence v3.0.
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Associated applications
- 201721 Dec
Certificate of Lawfulness for erection of a rear roof extension to main roof and outrigger with juliette…
This applicationRefusedOutlineP/2017/5351 - 201721 Dec
Formation of a basement and erection of a single storey rear infill extension
ApprovedHouseholderFiled alongsideP/2017/5352
Planning history at this site
1 other application at this property, newest first.
Planning constraints
Designations that overlap or adjoin the site outline.
- Flood zone 3: High probability (rivers and sea)
- Conservation area: Turnham Green
- Article 4 direction: Dwellinghouses (C3) to small HMOs (C4) - borough-wide Article 4 Direction
Possibly incomplete for this council: tree preservation orders.
Also checked, none recorded (21)
flood storage areas, listed buildings, green belt, scheduled monuments, World Heritage Sites, World Heritage Site buffer zones, registered parks and gardens, registered battlefields, Heritage at Risk entries, nutrient neutrality catchments, national parks, National Landscapes, SSSIs, Special Areas of Conservation, Special Protection Areas, Ramsar sites, ancient woodland, national nature reserves, local nature reserves, heritage coasts and brownfield registers.
A guide only, from official open data; it is not a planning search. Flood zones cover rivers and sea, not surface water.
Data © Crown copyright and others · sources and licences
Contains public sector information from planning.data.gov.uk (MHCLG and local planning authorities), licensed under the Open Government Licence v3.0. © Crown copyright and database right 2026.
© Historic England 2026. Contains Ordnance Survey data © Crown copyright and database right 2026. The Historic England GIS Data contained in this material was obtained on 2026-10-09. The most publicly available up to date Historic England GIS Data can be obtained from HistoricEngland.org.uk.
© Natural England copyright. Contains Ordnance Survey data © Crown copyright and database right 2026.
© Environment Agency copyright and/or database right 2026. All rights reserved. Flood Map for Planning, Open Government Licence v3.0.
Contains Ordnance Survey data © Crown copyright and database right 2026.
Source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2026.
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