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Loft Conversion Approval Rates in Harrow

Loft conversions change your roofline — and that makes them one of the more closely scrutinised application types. Councils scrutinise visibility, overlooking and street character more closely than for ground-level work. Here's what the data shows in Harrow.

88 real decisions·January 2020 to present·Updated March 2026
80.7%
Approval Rate
88
Decisions
71
Approved
17
Refused
80.7% approved. But 17 refused since 2020. Each refusal cost the homeowner time and money on drawings and application fees. Understanding your local data before you apply is the difference between confidence and a costly gamble.

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Why loft conversion approval rates matter

Loft conversions face more scrutiny than rear or side extensions because they change the property's profile from the street. Dormers, mansards and hip-to-gable alterations are particularly sensitive.

These are council averages. Your property is specific.

Two houses on the same street can get different outcomes.
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How loft conversions compare to other project types

Not all applications are treated equally. Here's how loft conversions stack up against other common projects in Harrow.

TypeDecisionsRate
Flat Conversion829
92.2%
Basement307
85.0%
Change of Use (Residential)642
83.8%
Wraparound Extension223
82.5%
Garage / Parking3,138
81.8%
Extension (General)684
81.4%
Conservatory317
81.4%
Loft Conversion88
80.7%
Outbuilding974
79.1%
New Build139
79.1%
Rear Extension4,812
78.2%
Dormer2,458
77.3%
Front Extension1,029
77.1%
HMO155
76.8%
Hip-to-Gable Conversion20
75.0%
Side Extension2,430
74.7%
Annex54
42.6%
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What the data tells us

1
80.7% of loft conversion applications in Harrow get approved. That means 17 homeowners since 2020 have been refused. Not terrible odds, but not a foregone conclusion.
3
Council averages are starting points, not guarantees. The decisions that matter most are the comparable ones near your specific property — because planning officers look at precedent, character and the immediate context of your street.

Before you spend £5,000+ on architects and drawings

17 loft conversion applications in Harrow have been refused since 2020. Many of those homeowners had already paid for drawings and application fees. A £79 report shows you what gets approved — and what gets refused — near your property.

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More Harrow planning data

Nearby councils loft conversion data

Methodology: Based on 88 planning decisions classified as loft conversions in Harrow, January 2020 to present. Classification uses keyword matching against proposal descriptions (matching generate_site_data.py rules). A single application may appear in multiple categories. Approval rate = approved / (approved + refused). Pending, withdrawn and invalid applications excluded. Data from Harrow Council's public planning portal. Full methodology →
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