Outbuilding approval rate in Hounslow

Hounslow approved 80.6% of outbuilding applications, based on 4,154 decisions analysed.

Last updated: March 2026

80.6%

outbuilding approval rate

4,154

Outbuilding decisions

3,348

Approved

806

Refused

87.7%

Hounslow overall

Outbuilding applications are refused more often than the Hounslow average (87.7%), suggesting the council scrutinises these projects more closely.

How outbuilding compares in Hounslow

Outbuilding (4,154 decided)

80.6%

Hounslow all applications (72,195 decided)

87.7%

Planning a outbuilding in Hounslow?

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Other project types in Hounslow

Rear Extension (26,504 decided)

84.9%

Loft Conversion (12,007 decided)

89.7%

Garage / Parking (8,713 decided)

88.6%

Side Extension (7,753 decided)

88.1%

New Build (4,779 decided)

90.0%

Hip-to-Gable Conversion (3,244 decided)

85.4%

Change of Use (Residential) (3,085 decided)

82.7%

Extension (General) (3,033 decided)

92.9%

Conservatory (1,925 decided)

95.0%

Wraparound Extension (1,494 decided)

88.9%

Basement (1,485 decided)

89.0%

Flat Conversion (1,402 decided)

72.9%

Dormer (1,373 decided)

90.5%

Front Extension (1,034 decided)

83.0%

HMO (338 decided)

49.7%

Annex (110 decided)

66.4%

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