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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?

80.6% get approved — but the odds vary by street. Your Pro Report shows exactly what gets approved and refused near your property.

✓ Your ward's outbuilding approval rate
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Less than one set of revised drawings.

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%
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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