Outbuilding approval rate in Harrow

Harrow approved 79.0% of outbuilding applications, based on 1,769 decisions analysed.

Last updated: June 2026

79.0%

outbuilding approval rate

1,769

Outbuilding decisions

1,397

Approved

372

Refused

75.9%

Harrow overall

Outbuilding applications are approved more often than the Harrow average (75.9%), suggesting the council is relatively receptive to these projects.

How outbuilding compares in Harrow

Outbuilding (1,769 decided)

79.0%

Harrow all applications (21,804 decided)

75.9%

Planning a outbuilding in Harrow?

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Other project types in Harrow

Rear Extension (10,512 decided)

75.3%

Dormer (4,257 decided)

74.6%

Side Extension (4,224 decided)

73.6%

Garage / Parking (3,654 decided)

76.3%

Front Extension (1,890 decided)

77.4%

Extension (General) (908 decided)

77.1%

Change of Use (Residential) (739 decided)

63.5%

Conservatory (582 decided)

81.1%

HMO (287 decided)

56.4%

Wraparound Extension (286 decided)

75.5%

Flat Conversion (274 decided)

63.1%

Basement (267 decided)

69.7%

Loft Conversion (117 decided)

70.1%

Annex (76 decided)

42.1%

Hip-to-Gable Conversion (66 decided)

86.4%

New Build (61 decided)

78.7%

← All Harrow planning statistics

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