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

Rear Extension Approval Rates in Islington

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 11,667 real decisions tell us about rear extension outcomes in Islington.

11,667 real decisions·January 2020 to August 2026·Updated August 2026
80.7%
Approval Rate
11,667
Decisions
9,417
Approved
2,250
Refused
80.7% approved. But 2,250 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.
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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 Islington.

TypeDecisionsRate
Conservatory1,665
85.9%
Outbuilding1,501
85.4%
Wraparound Extension223
83.0%
Basement10,639
82.3%
Rear Extension11,667
80.7%
Extension (General)5,803
80.7%
Side Extension1,924
80.1%
Front Extension129
79.1%
Annex90
78.9%
Change of Use (Residential)8,113
77.0%
Dormer3,491
76.5%
HMO321
76.0%
Garage / Parking3,076
72.9%
New Build2,076
71.7%
Loft Conversion6,059
67.2%
Flat Conversion1,422
67.2%
Hip-to-Gable Conversion41
53.7%
See how this applies to your postcode →

What the data tells us

1
80.7% of rear extension applications in Islington get approved. That means 2,250 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

2,250 rear extension applications in Islington 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 Islington planning data

Nearby councils rear extension data

Methodology: Based on 11,667 planning decisions classified as rear extensions in Islington, 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 Islington Council's public planning portal. Full methodology →
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