Grenville St Marys Hill Ascot SL5 9AP

This site has had 4 applications since 2023: 3 approved, 1 refused.

• 26/01933/NMA Granted

  Grenville St Marys Hill Ascot SL5 9AP

  Non material amendment to planning permission 25/03261/FULL for a reduction in the width and height of the side extension, increase in depth of side and rear extension and alterations to existing and proposed fenestration.

  Decided 2 Sep 2026 Amendments
• 25/02872/CPD Granted

  Grenville St Marys Hill Ascot SL5 9AP

  Certificate of lawfulness to determine whether the proposed part garage conversion, single storey front, side and rear extensions, 1no. outbuilding incidental to the main dwelling and alterations to fenestration are lawful.

  Decided 23 Dec 2025 Lawful development
• 23/00870/FULL Refused

  Grenville St Marys Hill Ascot SL5 9AP

  Alterations to front entrance canopy, single storey side extension, two storey side extension with 2no. Juliet balconies, new external front wall, 1no. EV charger, alterations to fenestration, external finishes and access and new dropped kerb following demolition of existing side element.

  Decided 29 Sep 2023 Full applications

1. 10 Dec 2025

   Received by Windsor and Maidenhead

2. 29 Jan 2026

   Decision issued: Application Permitted

3. 11 Aug 2026

   Added to PlanIndex

1 later application on the register refers to this one:

• 26/01933/NMA Granted

  Grenville St Marys Hill Ascot SL5 9AP

  Non material amendment to planning permission 25/03261/FULL for a reduction in the width and height of the side extension, increase in depth of side and rear extension and alterations to existing and proposed fenestration.

  Decided 2 Sep 2026 Amendments

Windsor and Maidenhead granted permission on 29 January 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.

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.

• Grenville St Marys Hill Ascot SL5 9AP

  25/02872/CPD Submitted 30 Oct 2025 50 yards away

  Certificate of lawfulness to determine whether the proposed part garage conversion, single storey front, side and rear extensions, 1no. outbuilding incidental to the main dwelling and alterations to fenestration are lawful.

  Granted Lawful development Extension Windows or glazing 12 docs
  Small domestic

• Grenville St Marys Hill Ascot SL5 9AP

  26/01933/NMA Submitted 5 Aug 2026 50 yards away

  Non material amendment to planning permission 25/03261/FULL for a reduction in the width and height of the side extension, increase in depth of side and rear extension and alterations to existing and proposed fenestration.

  Granted Amendments Extension Windows or glazing 10 docs

• Grenville St Marys Hill Ascot SL5 9AP

  23/00870/FULL Submitted 11 Apr 2023 50 yards away

  Alterations to front entrance canopy, single storey side extension, two storey side extension with 2no. Juliet balconies, new external front wall, 1no. EV charger, alterations to fenestration, external finishes and access and new dropped kerb following demolition of existing side element.

  Refused Full applications Extension Demolition +1 16 docs
  Small domestic

• Badgers Wood St Marys Hill Ascot SL5 9AP

  19/03175/NMA Submitted 14 Nov 2019 100 yards away

  Non material amendments to planning permission 19/01913/FULL for the increase in size of the ground floor to bring it into line with the front of the main house.

  Granted Amendments 5 docs

• 18 Norton Park Ascot SL5 9BW

  21/02746/FULL Submitted 9 Sep 2021 100 yards away

  Part single/part two storey front/side extension, single storey rear extension, single storey side extension, garage conversion into habitable accommodation and alteration to fenestration.

  Granted Full applications Extension Windows or glazing 15 docs
  Small domestic

• 9 Norton Park Ascot SL5 9BW

  23/01226/FULL Submitted 18 May 2023 100 yards away

  Single storey front/side extension, two single storey rear extensions, new chimney and alterations to fenestration.

  Granted Full applications Extension Windows or glazing 12 docs
  Small domestic

• 26/02029/FULL Granted

  5 Kimber Close Windsor SL4 4BJ

  Single storey rear extension.

  Received 17 Aug, published by the council 27 Aug 2026 Full applications
• 26/01955/FULL Granted

  2 Holmlea Road Datchet Slough SL3 9HQ

  Change of use from a dwellinghouse (Use Class C3) to a children's home (Use Class C2) for up to three children, together with conversion of the garage to an office with an en-suite facilities and alterations to fenestration.

  Received 7 Aug, published by the council 27 Aug 2026 Full applications
• 26/01121/FULL Granted

  Zain House 15 Wilton Crescent Windsor SL4 4YJ

  Single storey side/front extension, first floor extension over existing side element with 1no. Juliet balcony and 1no. Juliet balcony to existing rear elevation.

  Received 6 May, published by the council 11 Aug 2026 Full applications
• 26/01977/FULL Granted

  9 St Marks Place Windsor SL4 3BG

  Garage conversion and alterations to fenestration.

  Received 11 Aug, published by the council 24 Aug 2026 Full applications
• 26/01804/FULL Granted

  16 Devereux Road Windsor SL4 1JJ

  Installation of air conditioning compressor unit to the first floor side elevation.

  Received 23 Jul, published by the council 24 Aug 2026 Full applications