Data-backed planning intelligence · 3,780,000+ decisions analysed across England

Rear Extension Approval Rates in Sutton

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 7,274 real decisions tell us about rear extension outcomes in Sutton.

7,274 real decisions·January 2020 to August 2026·Updated August 2026
80.0%
Approval Rate
7,274
Decisions
5,822
Approved
1,452
Refused
80.0% approved. But 1,452 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 Sutton.

TypeDecisionsRate
Flat Conversion916
91.6%
Extension (General)2,228
89.0%
Basement235
84.7%
Conservatory419
84.5%
Dormer3,168
83.0%
Garage / Parking4,155
82.9%
Hip-to-Gable Conversion430
82.6%
Outbuilding856
82.0%
Change of Use (Residential)978
81.8%
Rear Extension7,274
80.0%
Wraparound Extension1,097
79.8%
Loft Conversion151
79.5%
Side Extension3,063
79.3%
New Build1,060
78.1%
Front Extension950
77.9%
HMO189
74.1%
Annex156
72.4%
See how this applies to your postcode →

What the data tells us

1
80.0% of rear extension applications in Sutton get approved. That means 1,452 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

1,452 rear extension applications in Sutton 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 3,780,000+ real decisions

More Sutton planning data

Nearby councils rear extension data

Methodology: Based on 7,274 planning decisions classified as rear extensions in Sutton, January 2020 to August 2026. 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 Sutton Council's public planning portal. Full methodology →
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