Skip to content
PlanIndex Get alerts
Menu

Planning application

139 Castellain Mansions Castellain Road London W9 1HG

Granted Westminster 25/08028/FULL Full Planning Permission Application

Works: Windows or glazing

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

Proposal

Replacement of existing sashes and door with double-glazed painted timber sashes and door.

As published by the council, reference 25/08028/FULL

Application record

Reference
25/08028/FULL
Type
Full Planning Permission Application
Status
Decided
Decision
Granted As published: Application Permitted
Received
5 Nov 2025
Validated
19 Nov 2025
Decided
20 Mar 2026
Ward
Maida Vale
Decision by
Delegated Decision
Postcode
W9 1HG

Timeline

Dates from the published record

  1. 5 Nov 2025

    Received by Westminster

  2. 19 Nov 2025

    Validated

    Checked as complete and ready for consideration.

  3. 20 Mar 2026

    Decision issued: Application Permitted

  4. 20 Jul 2026

    Added to PlanIndex

Who's behind it

Company information only, from the register and Companies House

Design Extension Agent, a design practice registered in Purley

Active · incorporated 2025 · Purley

132 applications on PlanIndex · across 24 councils · 75% granted

Trade members see everything this firm has filed, how it was decided, and get an email the day it files again.

See their track record

Documents

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

14 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.

Watch members (£5 a month) open the document list from here.

Open the documents

What this grant of permission means

Westminster granted permission on 20 March 2026, 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

  • 12 Lauderdale Parade Lauderdale Road London W9 1LU

    25/09224/FULL Submitted 19 Dec 2025 50 yards away

    Works to front forecourt relating to retention of canopy (Part Retrospective)

    Withdrawn Full applications 15 docs

  • 12 Lauderdale Parade Lauderdale Road London W9 1LU

    25/09223/FULL Submitted 19 Dec 2025 50 yards away

    88% historically approved · decision due ~13 Feb

    Works to front forecourt relating to retention of canopy (Part Retrospective)

    Awaiting decision Full applications 15 docs

  • 12 Lauderdale Parade Lauderdale Road London W9 1LU

    25/09225/FULL Submitted 19 Dec 2025 50 yards away

    88% historically approved · decision due ~13 Feb

    Installation of a new covered external area at the forecourt of the premises.

    Awaiting decision Full applications 16 docs

  • 70 Castellain Road London W9 1EX

    25/05836/FULL Submitted 18 Aug 2025 50 yards away

    Erection of new front dormer; erection of extension to rear roof slope; removal of chimney to rear; installation of raised parapet wall along west elevation with associated railings above parapet wall along the side and rear to form terrace on rear roof.

    Granted Full applications Extension Loft or dormer 15 docs

  • 66 Castellain Road London W9 1EX

    26/01168/TCA Submitted 24 Feb 2026 50 yards away

    100% historically approved · decision due ~21 Apr

    1 x Eucalyptus gunnii: crown reduce height by 2-3m, not exceeding 30% of crown volume, including selective shortening of extended upper and lateral branches to appropriate growth points in order to retain a balanced, natural crown form suitable to the species. Remove dead, dying, damaged and crossing branches throughout the crown. Light crown lift to achieve a clearance of approximately 2.5-3 metres above ground level, removing only secondary growth where necessary.

    Awaiting decision Trees 6 docs

  • 76 Castellain Road London W9 1EX

    05/03818/FULL Submitted 16 May 2005 50 yards away

    Use of 1st, 2nd and 3rd floors as 3 self contained flats (1x 2 bed, 1x 1 bed and one self-contained studio flat).

    Refused Full applications New dwelling 7 docs

In Westminster

  • 26/07528/FULL Awaiting decision

    69 Eaton Place London SW1X 8DF

    Installation of new cast iron water pipe on rear courtyard elevation. (Linked with 26/07529/LBC)

    Received 5 Nov, published by the council 6 Nov 2026 Full applications
  • 26/05200/FULL Decided

    1 The Court House 165 Seymour Place London W1H 4PU

    Installation of waterproofing system to the existing lead flat roofs

    Received 3 Aug, published by the council 28 Aug 2026 Full applications
  • 26/07521/FULL Awaiting decision

    Flat 18 Harlequin Court 20 Tavistock Street London WC2E 7NZ

    Installation of one external condenser unit

    Received 4 Nov, published by the council 6 Nov 2026 Full applications
  • 26/07508/FULL Awaiting decision

    Buckingham Palace The Mall London SW1A 1AA

    Replacement of existing security lighting to the Buckingham Palace Forecourt with 80 compact LED spotlights installed within the lantern clusters across 10 principal piers, with associated concealed cabling and reversible fixings. (Linked with 26/07509/LBC)

    Received 4 Nov, published by the council 5 Nov 2026 Full applications
  • 26/07472/FULL Awaiting decision

    Flat 3 82 New Cavendish Street London W1G 9TA

    Replacement windows to second floor level with vacuum, double glazing windows. (Linked with 26/07473/LBC)

    Received 3 Nov, published by the council 6 Nov 2026 Full applications