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

Side Extension approval rate in Harrow

Harrow approved 73.7% of side extension applications, based on 4,286 decisions analysed.

Last updated: August 2026

73.7%
side extension approval rate
4,286
Side Extension decisions
3,157
Approved
1,129
Refused
75.9%
Harrow overall

Side Extension applications are refused more often than the Harrow average (75.9%), suggesting the council scrutinises these projects more closely.

How side extension compares in Harrow

Side Extension (4,286 decided)
73.7%
Harrow all applications (22,151 decided)
75.9%

Planning a side extension in Harrow?

73.7% 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
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Other project types in Harrow

Rear Extension (10,671 decided)
75.4%
Dormer (4,314 decided)
74.6%
Garage / Parking (3,725 decided)
76.4%
Front Extension (1,922 decided)
77.3%
Outbuilding (1,794 decided)
78.8%
Extension (General) (923 decided)
76.7%
62.5%
Conservatory (588 decided)
80.8%
HMO (304 decided)
55.6%
Wraparound Extension (290 decided)
75.9%
Flat Conversion (278 decided)
63.3%
Basement (268 decided)
69.8%
Loft Conversion (119 decided)
70.6%
Annex (78 decided)
43.6%
86.4%
New Build (63 decided)
77.8%
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