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Rear Extension Approval Rates in Windsor & Maidenhead

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 2,140 real decisions tell us about rear extension outcomes in Windsor & Maidenhead.

2,140 real decisions·January 2020 to present·Updated June 2026
84.4%
Approval Rate
2,140
Decisions
1,807
Approved
333
Refused
84.4% approved. But 333 refused since 2020. Each refusal cost the homeowner time and money on drawings and application fees. Understanding your local data before you apply is the difference between confidence and a costly gamble.

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Why rear extension approval rates matter

Rear extensions sit in the middle of the pack nationally. They're common enough that councils have clear precedent — but that cuts both ways. If your neighbours have been refused, that precedent works against you too.

Ward gap in Windsor & Maidenhead: Belmont approves 100.0% of rear extension applications while Hurley And Walthams sits at 40.0%. That 60.0% gap means your postcode is one of the strongest indicators of outcome.

Rear Extension approval rate by ward

#WardDecisionsApprovedRate
1Belmont55
100.0%
2Pinkneys Green55
100.0%
3Datchet Horton And Wraysbury1110
90.9%
4Sunningdale And Cheapside65
83.3%
5Bisham And Cookham96
66.7%
6Bray64
66.7%
7Hurley And Walthams52
40.0%
See how this applies to your postcode →

These are council averages. Your property is specific.

A rear extension has a 100.0% approval rate in Belmont but just 40.0% in Hurley And Walthams.
Check your postcode to see what actually happens near your address.

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How rear extensions compare to other project types

Not all applications are treated equally. Here's how rear extensions stack up against other common projects in Windsor & Maidenhead.

TypeDecisionsRate
Loft Conversion274
89.1%
Hip-to-Gable Conversion135
88.1%
Basement97
87.6%
Conservatory192
87.0%
Front Extension598
84.6%
Rear Extension2,140
84.4%
Side Extension1,372
83.5%
Extension (General)211
83.4%
Garage / Parking1,537
82.3%
New Build146
80.8%
Dormer705
80.4%
Outbuilding557
78.6%
Change of Use (Residential)301
78.1%
Wraparound Extension121
76.0%
Annex43
62.8%
See how this applies to your postcode →

What the data tells us

1
84.4% of rear extension applications in Windsor & Maidenhead get approved. That means 333 homeowners since 2020 have been refused. Not terrible odds, but not a foregone conclusion.
2
Your ward matters more than you think. The 60.0% gap between Belmont (100.0%) and Hurley And Walthams (40.0%) means your postcode is one of the strongest indicators of outcome.
3
Council averages are starting points, not guarantees. The decisions that matter most are the comparable ones near your specific property — because planning officers look at precedent, character and the immediate context of your street.

Before you spend £5,000+ on architects and drawings

333 rear extension applications in Windsor & Maidenhead have been refused since 2020. Many of those homeowners had already paid for drawings and application fees. A free, property-specific report shows you what gets approved — and what gets refused — near your property.

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More Windsor & Maidenhead planning data

Nearby councils rear extension data

Methodology: Based on 2,140 planning decisions classified as rear extensions in Windsor & Maidenhead, January 2020 to present. Classification uses keyword matching against proposal descriptions (matching generate_site_data.py rules). A single application may appear in multiple categories. Approval rate = approved / (approved + refused). Pending, withdrawn and invalid applications excluded. Data from Windsor & Maidenhead Council's public planning portal. Full methodology →
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