Data-backed planning intelligence · 2,500,000+ decisions analysed across England

Rear Extension Approval Rates in Kensington & Chelsea

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 3,192 real decisions tell us about rear extension outcomes in Kensington & Chelsea.

3,192 real decisions·January 2020 to present·Updated March 2026
89.7%
Approval Rate
3,192
Decisions
2,864
Approved
328
Refused
89.7% approved. But 328 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.

These are council averages. Your property is specific.

Two houses on the same street can get different outcomes.
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 Kensington & Chelsea.

TypeDecisionsRate
Annex114
94.7%
Change of Use (Residential)2,016
94.1%
Garage / Parking1,852
92.8%
Flat Conversion484
92.6%
New Build552
92.4%
Basement7,111
92.3%
Extension (General)2,954
92.2%
HMO164
90.9%
Outbuilding790
90.8%
Rear Extension3,192
89.7%
Side Extension668
89.7%
Dormer1,190
89.2%
Conservatory898
89.0%
Front Extension43
88.4%
Loft Conversion1,827
86.4%
Wraparound Extension50
86.0%
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What the data tells us

1
89.7% of rear extension applications in Kensington & Chelsea get approved. That means 328 homeowners since 2020 have been refused. Not terrible odds, but not a foregone conclusion.
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

328 rear extension applications in Kensington & Chelsea 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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More Kensington & Chelsea planning data

Nearby councils rear extension data

Methodology: Based on 3,192 planning decisions classified as rear extensions in Kensington & Chelsea, 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 Kensington & Chelsea Council's public planning portal. Full methodology →
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