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Rear Extension Approval Rates in Slough

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 7,156 real decisions tell us about rear extension outcomes in Slough.

7,156 real decisions·January 2020 to present·Updated June 2026
83.7%
Approval Rate
7,156
Decisions
5,986
Approved
1,170
Refused
83.7% approved. But 1,170 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 Slough: Manor Park & Stoke approves 100.0% of rear extension applications while Britwell 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
1Manor Park & Stoke77
100.0%
2Upton Lea77
100.0%
3Upton55
100.0%
4Cippenham Manor87
87.5%
5Farnham76
85.7%
6Langley Meads65
83.3%
7Langley St. Marys53
60.0%
8Cippenham Green53
60.0%
9Haymill53
60.0%
10Britwell52
40.0%
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These are council averages. Your property is specific.

A rear extension has a 100.0% approval rate in Manor Park & Stoke but just 40.0% in Britwell.
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 Slough.

TypeDecisionsRate
Loft Conversion1,158
87.5%
Conservatory177
85.9%
Wraparound Extension920
85.7%
Dormer869
85.7%
Garage / Parking1,264
84.0%
Rear Extension7,156
83.7%
Hip-to-Gable Conversion358
83.2%
Side Extension2,806
82.5%
Outbuilding1,251
82.3%
Extension (General)328
81.4%
Annex28
78.6%
Change of Use (Residential)768
78.4%
Flat Conversion23
78.3%
Front Extension660
74.4%
New Build245
71.4%
HMO57
47.4%
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What the data tells us

1
83.7% of rear extension applications in Slough get approved. That means 1,170 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 Manor Park & Stoke (100.0%) and Britwell (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

1,170 rear extension applications in Slough 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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Free · Property report emailed in minutes · Based on 3,290,000+ real decisions

More Slough planning data

Nearby councils rear extension data

Methodology: Based on 7,156 planning decisions classified as rear extensions in Slough, 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 Slough Council's public planning portal. Full methodology →
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