Side Extension approval rate in Cardiff
Cardiff approved 65.6% of side extension applications, based on 154 decisions analysed.
Last updated: June 2026
65.6%
side extension approval rate
154
Side Extension decisions
101
Approved
53
Refused
81.7%
Cardiff overall
Side Extension applications are refused more often than the Cardiff average (81.7%), suggesting the council scrutinises these projects more closely.
How side extension compares in Cardiff
Side Extension
65.6%
Cardiff all applications
81.7%
Planning a side extension in Cardiff?
65.6% 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
67.9%
66.9%
66.6%
85.6%
70.2%
49.4%
77.8%
84.1%
82.8%
78.6%
88.5%
83.3%
71.4%
77.8%