Planning application
26/00306/CPD
15 The Avenue Old Windsor Windsor SL4 2RS
Proposal
Certificate of lawfulness to determine whether the proposed detached outbuilding incidental to the main dwelling is lawful.
As published by the council, reference 26/00306/CPD
Timeline
Dates from the published record
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4 Feb 2026
Received by Windsor and Maidenhead
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17 Feb 2026
Decision issued: Permitted Development
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25 Jul 2026
Added to PlanIndex
What a grant of permission means
The process from here
Permission has been granted, usually subject to conditions listed on the decision notice, some of which must be discharged before work starts. The decision notice on the council portal sets out exactly what was approved.
Work must normally begin within three years of the decision or the permission lapses. Neighbours cannot appeal a grant; challenging one means judicial review of how the decision was made, within tight time limits.
About lawful development applications
How this application type works
A lawful development certificate is a legal determination, not a planning judgement. It asks the council to confirm either that existing use or works are lawful, often through the passage of time, or that a proposal would not need planning permission at all. The applicant must prove the facts; the merits of the scheme are not considered.
Nearby applications
Within 500 metres
-
22/03322/CPD Granted
17 The Avenue Old Windsor Windsor SL4 2RS
Certificate of lawfulness to determine whether the loft conversion into habitable accommodation and x1 rear dormer is lawful.
-
22/03324/PDXL Granted
17 The Avenue Old Windsor Windsor SL4 2RS
Single storey rear extension no greater than 5.00m in depth, 3.65m high with an eaves height of 2.62m.
-
21/01334/CPD Granted
18 The Avenue Old Windsor Windsor SL4 2RS
Certificate of lawfulness to determine whether the proposed hip to gable, rear dormer and 3 No. front rooflights is lawful.
-
21/01803/FULL Granted
7 Meadow Way Old Windsor Windsor SL4 2NX
New front porch.
-
26/00906/CPD Granted
47 Cell Farm Avenue Old Windsor Windsor SL4 2PD
Certificate of lawfulness to determine whether the proposed hip to gable roof alteration is lawful.
-
22/02799/FULL Refused
6 Meadow Close Old Windsor Windsor SL4 2PB
Garage conversion, part single, part two storey rear extension, first floor front extension, 2no. front rooflights and 1no. rear dormer.
Other lawful development applications
In Windsor and Maidenhead
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26/01836/CPD Awaiting decision
Rivendale 22A Gloucester Drive Wraysbury Staines TW18 4TY
Certificate of lawfulness to determine whether the proposed conversion of the existing garage into habitable space is lawful.
-
26/01528/CPD Granted
Foxley Manor Forest Green Road Holyport Maidenhead SL6 2NW
Certificate of lawfulness to determine whether the proposed erection of an outbuilding is lawful.
-
26/01532/CPD Granted
72 Highway Avenue Maidenhead SL6 5AQ
Certificate of Lawfulness to determine whether the proposed rear dormer roof extension and associated internal alterations to enlarge the existing loft accommodation is lawful.
-
26/01823/CPD Awaiting decision
Highwood Corner Grubwood Lane Cookham Maidenhead SL6 9UB
Certificate of lawfulness to determine whether the proposed garage conversion, alterations to fenestration, 1 no. front dormer and 1 no. rear dormer to facilitate a loft conversion is lawful.
-
26/01772/CPD Granted
18 Broken Furlong Eton Windsor SL4 6PD
Certificate of lawfulness to determine whether the proposed erection of a single storey rear detached annex to be used incidental with the host dwelling is lawful.