Side Extension approval rate in Cardiff
Cardiff approved 59.3% of side extension applications, based on 108 decisions analysed.
Last updated: March 2026
59.3%
side extension approval rate
108
Side Extension decisions
64
Approved
44
Refused
81.9%
Cardiff overall
Side Extension applications are refused more often than the Cardiff average (81.9%), suggesting the council scrutinises these projects more closely.
How side extension compares in Cardiff
Side Extension
59.3%
Cardiff all applications
81.9%
Planning a side extension in Cardiff?
59.3% get approved — but the odds vary by street. Your Pro Report shows exactly what gets approved and refused near your property.
✓ Your ward's side extension approval rate
✓ Nearest comparable side extension decisions
✓ Refusal triggers specific to your area
✓ PDF report for your architect
Get Cardiff Pro Report — £79
✓ Nearest comparable side extension decisions
✓ Refusal triggers specific to your area
✓ PDF report for your architect
Less than one set of revised drawings.
Other project types in Cardiff
66.8%
63.0%
67.1%
48.8%
92.3%
70.1%
77.4%
91.7%
78.3%
90.9%
94.4%
86.7%
80.0%