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Most Common Planning Applications in Spelthorne

Not all planning applications are created equal. The gap between the highest and lowest approval project type in Spelthorne is 45.7% — that's the difference between near-certainty and a coin flip. What you build matters as much as where you build it.

1,484 real decisions·14 project types·Updated June 2026
89.6%
Safest: Conservatory
43.9%
Lowest: HMO
45.7%
Spread
14
Types ranked

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All 14 project types ranked

#TypeDecisionsApprovedRefusedRate
1Conservatory968610
89.6%
2Wraparound Extension63567
88.9%
3Outbuilding1008812
88.0%
4Front Extension72639
87.5%
5Rear Extension57148982
85.6%
6Side Extension20617531
85.0%
7Garage / Parking27521956
79.6%
8New Build514011
78.4%
9Dormer20015149
75.5%
10Extension (General)392910
74.4%
11Loft Conversion1208832
73.3%
12Hip-to-Gable Conversion826022
73.2%
13Change of Use (Residential)603723
61.7%
14HMO411823
43.9%
See how this applies to your postcode →

These are council averages. Your property is specific.

A conservatory application has a 89.6% approval rate. HMO? Just 43.9%.
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What the data tells us

1
The range is massive: 43.9% to 89.6%. Choosing the right project type — or framing your application correctly — can dramatically affect outcomes.
2
Visibility drives scrutiny. Project types that change the external appearance — dormers, loft conversions, hip-to-gable — face more resistance than those that don't. The more visible your proposal, the more carefully it needs designing.
3
These are council-wide averages. Your ward, your street and your immediate neighbours all shift the odds. The comparable decisions near your property are the best indicator of outcome.

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

205 planning applications in Spelthorne have been refused since 2020. Many of those homeowners had already paid for drawings and application fees. A free, property-specific report shows you what gets approved — and what gets refused — near your property.

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More Spelthorne planning data

Methodology: Classifies 1,484 decisions in Spelthorne into residential project types using keyword matching against proposal descriptions (matching generate_site_data.py subtype rules). A single application may appear in multiple categories. Data from Spelthorne Council's public planning portal, January 2020 to present. Full methodology →
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