Data-backed planning intelligence · 3,700,000+ decisions analysed across England, Scotland, Wales and Northern Ireland

Rear Extension approval rate in Cardiff

Cardiff approved 72.8% of rear extension applications, based on 467 decisions analysed.

Last updated: August 2026

72.8%
rear extension approval rate
467
Rear Extension decisions
340
Approved
127
Refused
82.4%
Cardiff overall

Rear Extension applications are refused more often than the Cardiff average (82.4%), suggesting the council scrutinises these projects more closely.

How rear extension compares in Cardiff

Rear Extension (467 decided)
72.8%
Cardiff all applications (5,184 decided)
82.4%

Planning a rear extension in Cardiff?

72.8% get approved, but the odds vary by street. Your Full Planning Analysis shows exactly what gets approved and refused near your property.

✓ Your ward's rear extension approval rate
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Other project types in Cardiff

Garage / Parking (332 decided)
68.7%
Extension (General) (315 decided)
67.9%
Dormer (275 decided)
84.0%
Loft Conversion (252 decided)
72.2%
Side Extension (208 decided)
72.1%
Conservatory (187 decided)
52.4%
66.9%
Outbuilding (96 decided)
77.1%
84.0%
HMO (50 decided)
80.0%
Front Extension (36 decided)
86.1%
Annex (32 decided)
78.1%
Flat Conversion (28 decided)
89.3%
84.6%
New Build (24 decided)
75.0%
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