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57, Mowbray Road, HA8 8JL

26/1388/FULFull planning permissionRefused
Full

Refused on 29 June 2026

2 reasons for refusal

Approximate site (title boundary)
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.

Proposal

Part single, part two storey side and rear extensions including conversion of the existing garage into habitable room, insertion of window to replace the garage door. Installation of lantern to rear. Raised terrace area with associated balustrades and external stairs to garden level. Raised trellis fencing alongside shared boundary. Formation of basement level. New front porch. Roof extension involving rear dormer window and 3no. front facing rooflights. Conversion into 2no. self-contained dwellings. Associated amenity space, refuse storage, cycle store, and off-street parking. (Part Retrospective)

Submitted
20 April 2026
  1. Received20 Apr
  2. Validated
  3. Consult.
  4. Target
  5. Decided29 Jun

Decided in 70 days (council typically 56)

About this application

This is a planning application for a dormer extension at 57, Mowbray Road, HA8 8JL. Barnet has handled 768 applications of this type. This one was decided in 70 days, 2 weeks longer than Barnet's typical decision time. There has been 1 other application at this address. In the past year there have been 54 applications across EY22. We hold 1,449 applications in total for the HA8 postcode area.

62% of full planning permission applications at London Borough of Barnet were approved. Across all application types, the council typically decides in about 8 weeks (median).

Based on decided applications received in the last 3 years.See what's approved near your address

Why it was refused

  1. The proposed sub-division of the property to form 2no. self-contained flats, by reason of its location within a road characterised by single family dwellinghouses, would be incongruous to the established pattern of development and contribute towards change in the function and character of the street. As such the proposal would be contrary to Policy D3 of the London Plan (2021) and Policies CDH01 and HOU03 of the adopted Barnet Local Plan 2025 and the Residential Design Guidance SPD 2016.
  2. The proposed conversion of the dwellinghouse into two 4 bed self contained units would result in an over intensive use of the property leading to unacceptable levels of noise and disturbance by way of increased comings-and-goings and general activity, to the detriment of the residential amenities of neighbouring occupiers, contrary to Policies D3 and D14 of the London Plan (2021), Policies CDH01 of the Adopted Barnet Local Plan (2025), the Residential Design Guidance SPD (2016) and the Sustainable Design and Construction SPD (2016).

From the council's decision notice.

Application details

Postcode
HA8 8JL
Application type
Full planning permission

Site constraints

Checking the site
2/3
Council recordsAppealsFlood risk

Designations that overlap or adjoin the site outline.

  • Article 4 direction: Article 4 Small Houses in Multiple Occupation (HMO) Area 1
  • Flood zone 1: Low probability (rivers and sea)
Also checked, none recorded (23)

flood storage areas, conservation areas, listed buildings, tree preservation orders, 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 2026-11-03. 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.

Source: Barnet

Contains public sector information from the Planning London Datahub, licensed under the Open Government Licence v3.0.

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