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74 Thurlow Hill London Lambeth SE21 8JN

25/04003/FULFull Planning PermissionRefused
Full

Refused on 17 February 2026

Council decision: Refuse PermissionDelegated (officer decision)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

Erection of a first floor side extension, and alteration to the ground floor front elevation comprising removal of an existing door and window and installation of a replacement window.

Received
23 December 2025
Decision level
Delegated (officer decision)
Ward
West Dulwich
Agent
Planners & Architects
  1. Received23 Dec
  2. Validated23 Dec
  3. Consult.27 Jan
  4. Target17 Feb
  5. Decided17 Feb

Decided in 56 days (council typically 56)

About this application

This is a full planning application for a side extension at 74 Thurlow Hill London Lambeth SE21 8JN. Lambeth has handled 398 applications of this type. This one was decided in 56 days. There have been 3 other applications at this address. In the past year there have been 52 applications across West Dulwich. We hold 1,059 applications in total for the SE21 postcode area.

70% of full applications at London Borough of Lambeth 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 extension by reason of its design and siting, would unbalance the pair of semi detached dwellings and would fail to maintain a separation from the shared boundary, resulting in harm to the character and appearance of the host dwelling and the wider street scene. The proposal is therefore contrary to Policies Q5 and Q11 of the LLP (2021) and the guidance in the SPD (2023).
  2. The proposed extension by reason of its siting and increased height on the boundary would result in an overbearing and unneighbourly development through loss of outlook. In the absence of a detailed daylight and sunlight assessment, it is considered that the proposal would give rise to an unacceptable impact through London planning@lambeth.gov.uk SW2 9QQ increased overshadowing and loss of light to neighbouring dwellings. The proposal is therefore contrary to policy Q2 of the Lambeth Local Plan (2021) and the guidance in the SPD (2023).

From the council's decision notice.

Application details

Postcode
SE21 8JN
Application type
Full Planning Permission
Scale / size
Small

Planning application dates

Date validated
23 December 2025
Consultation expiry
27 January 2026
Consultation end
27 January 2026
Neighbour consultation end
27 January 2026
Target decision date
17 February 2026

Applicant and agent

Agent
Planners & Architects
Agent address
443 Streatham High Road London SW16 3PH

Planning decision

Statutory period
56 days

Additional information

Comments
0
Documents
20
Constraints
2

Site constraints

Checking the site
2/3
Council recordsAppealsFlood risk

Designations that overlap or adjoin the site outline.

  • Flood zone 1: Low probability (rivers and sea)
Also checked, none recorded (24)

flood storage areas, conservation areas, listed buildings, Article 4 directions, 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.

Associated applications

  1. 2025
    23 Dec

    Application for a Certificate of Lawful Certificate (Proposed) for the erection of a hip-to-gable rear dormer…

    ApprovedCertificate of Lawful Use proposedFiled alongside25/04002/LDCP
  2. 2025
    23 Dec

    Erection of a first floor side extension, and alteration to the ground floor front elevation comprising…

    This applicationRefusedFull25/04003/FUL

Source: Lambeth

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

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