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Annex approval rate in Cardiff

Cardiff approved 78.3% of annex applications, based on 23 decisions analysed.

Last updated: March 2026

78.3%
annex approval rate
23
Annex decisions
18
Approved
5
Refused
81.9%
Cardiff overall

Annex applications are refused more often than the Cardiff average (81.9%), suggesting the council scrutinises these projects more closely.

How annex compares in Cardiff

Annex (23 decided)
78.3%
Cardiff all applications (4,367 decided)
81.9%

Planning a annex in Cardiff?

78.3% get approved — but the odds vary by street. Your Pro Report shows exactly what gets approved and refused near your property.

✓ Your ward's annex approval rate
✓ Nearest comparable annex decisions
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Less than one set of revised drawings.

Other project types in Cardiff

Extension (General) (271 decided)
66.8%
Rear Extension (265 decided)
63.0%
Garage / Parking (249 decided)
67.1%
Conservatory (172 decided)
48.8%
Dormer (168 decided)
92.3%
Loft Conversion (164 decided)
70.1%
Side Extension (108 decided)
59.3%
55.1%
Outbuilding (62 decided)
77.4%
91.7%
Flat Conversion (22 decided)
90.9%
HMO (18 decided)
94.4%
New Build (15 decided)
86.7%
Front Extension (10 decided)
80.0%
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