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Rear Extension Approval Rates in Croydon

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 10,142 real decisions tell us about rear extension outcomes in Croydon.

10,142 real decisions·January 2020 to present·Updated March 2026
81.1%
Approval Rate
10,142
Decisions
8,224
Approved
1,918
Refused
81.1% approved. But 1,918 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 Croydon: WT18 approves 100.0% of rear extension applications while POR18 sits at 60.0%. That 40.0% gap means your postcode is one of the strongest indicators of outcome.

Rear Extension approval rate by ward

#WardDecisionsApprovedRate
1WT1866
100.0%
2SHN1855
100.0%
3BM1865
83.3%
4POR1853
60.0%
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 WT18 but just 60.0% in POR18.
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 Croydon.

TypeDecisionsRate
Conservatory604
84.9%
Extension (General)1,739
81.4%
Rear Extension10,142
81.1%
Front Extension1,008
79.5%
Basement1,704
79.5%
Side Extension4,960
79.4%
Dormer4,807
79.2%
New Build5,099
78.2%
Garage / Parking10,172
77.8%
Wraparound Extension982
77.6%
Hip-to-Gable Conversion1,267
76.6%
Loft Conversion2,549
75.8%
Outbuilding1,457
74.1%
Annex208
71.2%
Change of Use (Residential)1,701
60.6%
Flat Conversion613
49.4%
HMO678
49.4%
See how this applies to your postcode →

What the data tells us

1
81.1% of rear extension applications in Croydon get approved. That means 1,918 homeowners since 2020 have been refused. Not terrible odds, but not a foregone conclusion.
2
Your ward matters more than you think. The 40.0% gap between WT18 (100.0%) and POR18 (60.0%) 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

1,918 rear extension applications in Croydon have been refused since 2020. Many of those homeowners had already paid for drawings and application fees. A £79 report shows you what gets approved — and what gets refused — near your property.

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Free instant check · Pro Report £79 · Based on 2,500,000+ real decisions

More Croydon planning data

Nearby councils rear extension data

Methodology: Based on 10,142 planning decisions classified as rear extensions in Croydon, 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 Croydon Council's public planning portal. Full methodology →
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