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Rear Extension Approval Rates in Barnet

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 17,196 real decisions tell us about rear extension outcomes in Barnet.

17,196 real decisions·January 2020 to present·Updated March 2026
75.9%
Approval Rate
17,196
Decisions
13,051
Approved
4,145
Refused
75.9% approved. But 4,145 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.

Rear Extension approval rate by ward

#WardDecisionsApprovedRate
1CH22117
63.6%
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These are council averages. Your property is specific.

Two houses on the same street can get different outcomes.
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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 Barnet.

TypeDecisionsRate
Basement2,575
83.5%
Extension (General)1,244
82.7%
Garage / Parking10,560
82.6%
Hip-to-Gable Conversion3,471
82.3%
Side Extension6,503
81.8%
New Build1,933
81.8%
Conservatory1,489
81.8%
Dormer9,213
81.2%
Loft Conversion8,125
80.9%
Wraparound Extension2,881
80.4%
Front Extension1,766
78.9%
Outbuilding3,104
78.6%
Flat Conversion4,171
76.4%
Rear Extension17,196
75.9%
Annex205
72.2%
Change of Use (Residential)1,973
69.6%
HMO581
44.4%
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What the data tells us

1
75.9% of rear extension applications in Barnet get approved. That means 4,145 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

4,145 rear extension applications in Barnet 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 Barnet planning data

Nearby councils rear extension data

Methodology: Based on 17,196 planning decisions classified as rear extensions in Barnet, 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 Barnet Council's public planning portal. Full methodology →
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