Planning application
Grenville St Marys Hill Ascot SL5 9AP
Works: Extension Windows or glazing Small domestic
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
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.
As published by the council, reference 25/02872/CPD
Application record
- Reference
- 25/02872/CPD
- Type
- Cert of Lawfulness of Proposed Dev
- Status
- Decided
- Decision
- Permitted Development
- Received
- 30 Oct 2025
- Validated
- 3 Nov 2025
- Decided
- 23 Dec 2025
- Ward
- Ascot & Sunninghill
- Parish
- Sunninghill And Ascot Parish
- Decision by
- Delegated
- Postcode
- SL5 9AP
Site history
Applications at this address on the Windsor and Maidenhead register
This site has had 3 applications since 2025: 3 approved, 0 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.
-
25/03261/FULL Granted
Grenville St Marys Hill Ascot SL5 9AP
Single storey front extension and single storey rear/side extension following demolition of existing elements.
Timeline
Dates from the published record
-
30 Oct 2025
Received by Windsor and Maidenhead
-
3 Nov 2025
Validated
Checked as complete and ready for consideration.
-
23 Dec 2025
Decision issued: Permitted Development
-
11 Aug 2026
Added to PlanIndex
Documents
Plans, drawings, consultee responses and the officer's report
12 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.
Trade members open them from here.
Open the documentsWhat this grant of permission means
Windsor and Maidenhead granted permission on 23 December 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 lawful development applications
A lawful development certificate is a legal determination that existing or proposed works do not need planning permission; the merits of the scheme are not considered. More in our guide to planning application types.
Nearby applications
Within 500 metres
-
Grenville St Marys Hill Ascot SL5 9AP
Single storey front extension and single storey rear/side extension following demolition of existing elements.
Granted Full applications Extension Demolition 15 docsSmall domestic -
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.
Granted Amendments Extension Windows or glazing 10 docs -
Badgers Wood St Marys Hill Ascot SL5 9AP
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
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 docsSmall domestic -
9 Norton Park Ascot SL5 9BW
Single storey front and rear extensions with new chimney to the side elevation and alterations to fenestration.
Granted Full applications Extension Windows or glazing 12 docsSmall domestic -
18 Norton Park Ascot SL5 9BW
Non material amendments to planning permission 21/02746/FULL for the addition of a ground floor rear window to replace the existing patio door, addition of a front first floor window following the removal of the gable vent and an increase in size of the first floor rear window.
Granted Amendments Windows or glazing 11 docs
Other lawful development applications
In Windsor and Maidenhead
-
26/00501/CPU Refused
143 Cookham Road Maidenhead SL6 7EU
Certificate of lawfulness to determine whether the proposed use of the dwelling as a small childrens home for up to two children and two carers is lawful.
-
26/01763/CPU Refused
Land At The Junction of Warners Hill And Dean Lane Cookham Maidenhead
Certificate of lawfulness to determine whether the proposed use of the land as an orchard with mobile poultry run and polytunnel is lawful.
-
26/01615/CLU Granted
Riding Court Farm Riding Court Riding Court Road Datchet Slough SL3 9JT
Certificate of lawfulness to determine whether the existing units 'JKL' (use class B8) used for storage and distribution; unit 'AB' (use class B8) used for hiring, maintaining, and cleaning concrete screed and machinery and 'storage yard 2' (use class B8) used for the storage of scaffolding is lawful.
-
26/01581/CLD Granted
The George Public House The Brewhouse The Green Holyport Road Holyport Maidenhead
Certificate of lawfulness to determine whether the existing bollard is lawful.
-
26/02117/CPD Awaiting decision
27 Tyrell Gardens Windsor SL4 4DH
Certificate of lawfulness to determine whether the proposed garage conversion is lawful.