15 Blanche Lane South Mimms Potters Bar Hertfordshire EN6 3NY

26/0061/FULFull Planning PermissionRefused

Full

Refused on 5 November 2026

Council decision: Refuse Permission1 reason 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

Demolition of existing detached bungalow to facilitate construction of 3x two storey dwellings (2x semi-detached and 1x detached) to include hard and soft landscaping, front boundary works to include new crossover and erection of cycle and bin storage.

Received: 20 January 2026
Public comments: 1 · last counted 13 October 2026
Council: Hertsmere Borough Council
Ward: Shenley
Agent: Henry Planning LTD

ReceivedReceived20 Jan
ValidatedValidated3 Feb
Consult.Consultation3 Mar
TargetTarget Date1 Jul
DecidedDecided5 Nov

Decided in 275 days (council typically 56)

About this application

This is a full planning application for demolition at 15 Blanche Lane South Mimms Potters Bar Hertfordshire EN6 3NY. Hertsmere has handled 1,861 applications of this type. This one was decided in 289 days, 33 weeks longer than Hertsmere's typical decision time. There have been 7 other applications at this address. In the past year there have been 124 applications across Shenley. We hold 3,353 applications in total for the EN6 postcode area.

90% of full applications at Hertsmere Borough Council 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.Planning something similar? See what gets approved on your street

Why it was refused

The applicant has failed to provide sufficient and reliable information to demonstrate compliance with the mandatory Biodiversity Net Gain requirements set out in Schedule 7A of the Town and Country Planning Act 1990 (as amended by the Environment Act 2021). The submitted Biodiversity Net Gain Assessment fails to adequately account for the substantial clearance of trees and vegetation from the site after 30 January 2020 and, as a consequence, does not establish an accurate biodiversity baseline from which biodiversity gain can be assessed. This is contrary to the BNG requirements of The Environment Act 2023, the NPPF (2026), Policies SADM12 and CS12 of the adopted local plan, Biodiversity, Trees and Landscape SPD (2010), and Biodiversity Net Gain Draft Supplementary Planning Document (2022).

From the council's decision notice.

Application details

Postcode: EN6 3NY
Application type: Full Planning Permission
Scale / size: Medium
Parish: The Parish Council South Mimms And Ridge

Planning application dates

Date validated: 3 February 2026
Consultation expiry: 3 March 2026
Consultation start: 10 February 2026
Consultation end: 3 March 2026
Neighbour consultation start: 5 February 2026
Neighbour consultation end: 26 February 2026
Last date for comments: 3 March 2026
Target decision date: 1 July 2026

Applicant and agent

Applicant: Private applicant
Agent: Henry Planning LTD
Agent address: 163 Church Hill Road East Barnet Barnet EN4 8PQ

Planning decision

Case officer: Monika Vistartaite
Statutory period: 148 days

Additional information

Planning Portal ID: PP-14633714
Documents: 26
Constraints: 8

Site constraints

Checking the site

2/3

Council recordsAppealsFlood risk

Designations that overlap or adjoin the site outline.

Green belt: Hertsmere
Flood zone 1: Low probability (rivers and sea)

Not published by this council, so not checked: Article 4 directions. Ask the council if these matter.

Possibly incomplete for this council: tree preservation orders.

Also checked, none recorded (21)

flood storage areas, conservation areas, listed buildings, 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.

Planning history at this site

7 other applications at this property, newest first.

Source: Hertsmere

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