Side Extension approval rate in Cardiff
Cardiff approved 72.1% of side extension applications, based on 208 decisions analysed.
Last updated: August 2026
72.1%
side extension approval rate
208
Side Extension decisions
150
Approved
58
Refused
82.4%
Cardiff overall
Side Extension applications are refused more often than the Cardiff average (82.4%), suggesting the council scrutinises these projects more closely.
How side extension compares in Cardiff
Side Extension
72.1%
Cardiff all applications
82.4%
Planning a side extension in Cardiff?
72.1% 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 side extension approval rate
✓ Nearest comparable side extension decisions
✓ Refusal triggers specific to your area
✓ PDF report for your architect
Free planning check for Cardiff →
✓ Nearest comparable side extension decisions
✓ Refusal triggers specific to your area
✓ PDF report for your architect
Other project types in Cardiff
72.8%
68.7%
67.9%
84.0%
72.2%
52.4%
77.1%
84.0%
80.0%
86.1%
78.1%
89.3%
84.6%
75.0%