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Rear Extension Approval Rates in South Downs

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 978 real decisions tell us about rear extension outcomes in South Downs.

978 real decisions·January 2020 to August 2026·Updated August 2026
93.4%
Approval Rate
978
Decisions
913
Approved
65
Refused
93.4% approved. But 65 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 South Downs.

TypeDecisionsRate
Conservatory371
94.9%
Outbuilding921
94.9%
Basement68
94.1%
Extension (General)809
93.6%
Rear Extension978
93.4%
Front Extension110
92.7%
Side Extension547
92.3%
Garage / Parking1,505
90.6%
Annex202
89.1%
Dormer420
88.1%
Wraparound Extension73
86.3%
New Build242
84.7%
Loft Conversion159
83.6%
Change of Use (Residential)400
82.0%
Hip-to-Gable Conversion33
75.8%
See how this applies to your postcode →

What the data tells us

1
93.4% of rear extension applications in South Downs get approved. That means 65 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

65 rear extension applications in South Downs 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 South Downs planning data

Nearby councils rear extension data

Methodology: Based on 978 planning decisions classified as rear extensions in South Downs, 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 South Downs Council's public planning portal. Full methodology →
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