Planning application
17 Hertford Street London W1J 7RS
Works: Extension Loft or dormer Small domestic
Read from the description, not a valuation. How we read the register
Still open. Anyone can comment while the consultation period runs, and comments go to the council rather than to us.
Proposal
Replacement of the mansard infill extension to the south east of the property by extending the existing bay upwards by a single storey (3-storeys total) and associated roof works to improve the internal space. (Linked with 26/03410/LBC)
As published by the council, reference 26/03409/FULL
Application record
- Reference
- 26/03409/FULL
- Type
- Full Planning Permission Application
- Status
- Pending
- Received
- 22 May 2026
- Validated
- 11 Jun 2026
- Ward
- West End
- Postcode
- W1J 7RS
Site history
Applications at this address on the Westminster register
This site has had 11 applications since 2007: 3 approved, 0 refused.
-
26/06165/LBC Decided
17 Hertford Street London W1J 7RS
Internal alterations to the basement including new lightweight timber-stud partitions to reorganise the existing basement layout; Installation of new sanitaryware in a newly configured bathroom; Replacement of modern kitchen fittings; and Installation of traditional four-panel timber doors, architraves and ironmongery designed to match existing doors.
-
26/03484/ADLBC Decided
17 Hertford Street London W1J 7RS
Details of all new windows / reduction in size of dormer windows / facing materials pursuant to conditions 4, 5 and 7 of listed building consent dated 13 February 2025 (RN: 24/03932/LBC) [Linked to 26/03406/ADFULL]
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26/03410/LBC Awaiting decision
17 Hertford Street London W1J 7RS
Replacement of the mansard infill extension to the south east of the property by extending the existing bay upwards by a single storey (3-storeys total) and associated roof works to improve the internal space. (Linked with 26/03409/FULL)
-
26/03406/ADFULL Decided
17 Hertford Street London W1J 7RS
Details of all new windows / reduction in size of dormer windows / facing materials pursuant to conditions 4, 5 and 6 of planning permission dated 13 February 2025 (RN: 24/03931/FULL) [Linked to 26/03484/ADLBC]
-
26/02817/FULL Withdrawn
17 Hertford Street London W1J 7RS
Replacement of non-original casement windows at Level 03 with timber sash windows; new structure for mansard extension, infill of existing lightwell and repositioning of skylight above stairwell. [Linked to 26/02818/LBC]
-
26/02818/LBC Awaiting decision
17 Hertford Street London W1J 7RS
Replacement of non-original casement windows at Level 03 with timber sash windows; new structure for mansard extension, infill of existing lightwell and repositioning of skylight above stairwell. [Linked to 26/02817/FULL]
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25/07827/FULL Withdrawn
17 Hertford Street London W1J 7RS
Addition of a fourth-floor mansard roof to allow for the creation of a one-bedroom apartment for short term letting purposes, replacement of windows at third floor level, internal and external restoration, redecoration and minor reconfigurations and other associated works. (Linked 25/07828/LBC)
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25/07828/LBC Granted
17 Hertford Street London W1J 7RS
Internal reconfigurations, restoration and associated works.
-
07/01340/LBC Granted
17 Hertford Street London W1J 7RS
Installation of nine air-conditioning units at roof level and replacement of roof access enclosure and rooflight; installation of associated internal units and pipework.
-
07/01339/FULL Granted
17 Hertford Street London W1J 7RS
Installation of nine air-conditioning units at roof level and replacement of roof access enclosure and rooflight.
Timeline
Dates from the published record
-
22 May 2026
Received by Westminster
-
11 Jun 2026
Validated
Checked as complete and ready for consideration.
-
21 Jul 2026
Added to PlanIndex
-
Decision
Awaiting decision
Decision expected by 6 August 2026, 8 weeks from validation under the statutory target for most applications. Extensions of time are common and are agreed case by case.
Westminster took a median of 91 days over the applications it decided in the last year.
Who's behind it
Company information only, from the register and Companies House
Arya Douge Agent, registered in London
Active · incorporated 2021 · London
15 applications on PlanIndex · across 3 councils
Trade members see everything this firm has filed, how it was decided, and get an email the day it files again.
See their track recordDocuments
Plans, drawings, consultee responses and the officer's report
32 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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Open the documentsWhat happens while it is decided
This application is with Westminster for determination, against a statutory target of eight weeks. Over the last year Westminster decided full applications in a median of 119 days. More in our guide to how long planning decisions take.
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
-
17 Hertford Street London W1J 7RS
Addition of a fourth-floor mansard roof to allow for the creation of a one-bedroom apartment for short term letting purposes, replacement of windows at third floor level, internal and external restoration, redecoration and minor reconfigurations and other associated works. (Linked 25/07828/LBC)
Withdrawn Full applications Loft or dormer Windows or glazing 37 docs -
17 Hertford Street London W1J 7RS
Internal reconfigurations, restoration and associated works.
Granted Heritage and listed buildings 56 docs -
17 Hertford Street London W1J 7RS
90% historically approved · decision due ~6 Aug
Replacement of the mansard infill extension to the south east of the property by extending the existing bay upwards by a single storey (3-storeys total) and associated roof works to improve the internal space. (Linked with 26/03409/FULL)
Awaiting decision Heritage and listed buildings Extension Loft or dormer 28 docsSmall domestic -
17 Hertford Street London W1J 7RS
Replacement of non-original casement windows at Level 03 with timber sash windows; new structure for mansard extension, infill of existing lightwell and repositioning of skylight above stairwell. [Linked to 26/02818/LBC]
Withdrawn Full applications Extension Loft or dormer +1 1 doc -
17 Hertford Street London W1J 7RS
90% historically approved · decision due ~23 Jun
Replacement of non-original casement windows at Level 03 with timber sash windows; new structure for mansard extension, infill of existing lightwell and repositioning of skylight above stairwell. [Linked to 26/02817/FULL]
Awaiting decision Heritage and listed buildings Extension Loft or dormer +1 1 doc -
17 Hertford Street London W1J 7RS
Installation of nine air-conditioning units at roof level and replacement of roof access enclosure and rooflight; installation of associated internal units and pipework.
Granted Heritage and listed buildings Loft or dormer 2 docs
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