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Planning application

4 Mill Street London W1S 2AX

Granted Westminster 25/05998/FULL Full Planning Permission Application

Works: New dwelling Extension Windows or glazing Several homes

Read from the description, not a valuation. How we read the register

Permission granted. Work must normally begin within three years of the decision or the permission lapses.

Proposal

Erection of a rear roof extension at third floor level with a sedum roof to the rear; replacement of windows at second floor level with double glazing timber windows; replacement of door and window to the existing rear first floor extension with double glazing timber windows including replacement of roofing; and associated works all in connection with the use of the first to third floor as four flats (Class C3)

As published by the council, reference 25/05998/FULL

Application record

Reference
25/05998/FULL
Type
Full Planning Permission Application
Status
Decided
Decision
Granted As published: Application Permitted
Received
22 Aug 2025
Validated
5 Sep 2025
Decided
28 Oct 2025
Ward
West End
Decision by
Delegated Decision
Postcode
W1S 2AX

Timeline

Dates from the published record

  1. 22 Aug 2025

    Received by Westminster

  2. 5 Sep 2025

    Validated

    Checked as complete and ready for consideration.

  3. 28 Oct 2025

    Decision issued: Application Permitted

  4. 21 Jul 2026

    Added to PlanIndex

Who's behind it

Company information only, from the register and Companies House

4D Planning Agent, a planning consultancy

191 applications on PlanIndex · across 41 councils · 63% granted

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Documents

Plans, drawings, consultee responses and the officer's report

29 documents on file for this application

A planning file usually holds the application form, drawings and site plans, consultee responses, the officer's report and the decision notice.

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What this grant of permission means

Westminster granted permission on 28 October 2025, subject to any conditions on the decision notice. Work must normally begin within three years or the permission lapses. More in our guide to what happens after a planning decision.

About full applications

A full application seeks permission for a complete, detailed proposal in one go, with siting, design, access and landscaping all fixed at this stage. More in our guide to planning application types.

Nearby applications

Within 0.3 miles

  • 6 - 8 Mill Street London W1S 2AZ

    26/06892/FULL Submitted 9 Oct 2026 50 yards away

    88% historically approved · decision due ~4 Dec

    Variation of condition 1 of planning permission dated 31 August 2023 (RN:23/03515/FULL) for the: Relocation of air conditioning units from rear first floor roof to second floor rear flat roof, railings to second floor flat roof, installation of tiles to exterior rear ground floor level and installation of uplighters to the front facade. NAMELY, to allow provision of railings to two small back of house flat roofs (Application under section 73 of the Act).

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  • 6 - 8 Mill Street London W1S 2AZ

    26/02839/ADFULL Submitted 29 Apr 2026 50 yards away

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    25/06233/FULL Submitted 2 Sep 2025 50 yards away

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    26/01398/ADFULL Submitted 4 Mar 2026 50 yards away

    88% historically approved · decision due ~29 Apr

    Details of waste storage arrangements pursuant to Condition 5 of the planning permission dated 7 June 2016 (RN: 15/06533/FULL)

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  • Second Floor 16 Conduit Street London W1S 2XL

    26/01480/NMA Submitted 9 Mar 2026 50 yards away

    93% historically approved · decision due ~4 May

    Amendment of planning permission dated 7 June 2016 (RN: 15/06533/FULL) for 'Dual/alternative use of the second floor for either office (Class B1a) or residential (Class C3) use (1 x 2 bedroom unit). Installation of 4 x external grilles at second floor level on the Mill Street elevation and 1 x external grille on Conduit Street elevation'. NAMELY to vary the wording of Condition 6 to allow the implementation of an alternative ventilation strategy.

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