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Rear Extension Approval Rates in Lewisham

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 4,494 real decisions tell us about rear extension outcomes in Lewisham.

4,494 real decisions·January 2020 to present·Updated March 2026
75.4%
Approval Rate
4,494
Decisions
3,390
Approved
1,104
Refused
75.4% approved. But 1,104 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 rear extension approval rates matter

Rear extensions sit in the middle of the pack nationally. They're common enough that councils have clear precedent — but that cuts both ways. If your neighbours have been refused, that precedent works against you too.

Ward gap in Lewisham: Hither Green approves 100.0% of rear extension applications while Catford South sits at 66.7%. That 33.3% gap means your postcode is one of the strongest indicators of outcome.

Rear Extension approval rate by ward

#WardDecisionsApprovedRate
1Hither Green55
100.0%
2Perry Vale55
100.0%
3Lee Green54
80.0%
4Catford South64
66.7%
See how this applies to your postcode →

These are council averages. Your property is specific.

A rear extension has a 100.0% approval rate in Hither Green but just 66.7% in Catford South.
Check your postcode to see what actually happens near your address.

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How rear extensions compare to other project types

Not all applications are treated equally. Here's how rear extensions stack up against other common projects in Lewisham.

TypeDecisionsRate
New Build299
89.0%
Extension (General)2,648
84.2%
Flat Conversion2,727
84.0%
Wraparound Extension420
84.0%
Garage / Parking3,589
83.2%
Basement1,223
82.7%
Conservatory352
82.7%
Outbuilding796
82.3%
Hip-to-Gable Conversion853
81.7%
Dormer1,945
80.9%
Loft Conversion2,555
79.3%
Change of Use (Residential)1,997
79.2%
Rear Extension4,494
75.4%
Side Extension1,146
75.4%
Annex77
67.5%
HMO442
64.5%
Front Extension55
60.0%
See how this applies to your postcode →

What the data tells us

1
75.4% of rear extension applications in Lewisham get approved. That means 1,104 homeowners since 2020 have been refused. Not terrible odds, but not a foregone conclusion.
2
Your ward matters more than you think. The 33.3% gap between Hither Green (100.0%) and Catford South (66.7%) means your postcode is one of the strongest indicators of outcome.
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

1,104 rear extension applications in Lewisham 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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Free instant check · Pro Report £79 · Based on 2,500,000+ real decisions

More Lewisham planning data

Nearby councils rear extension data

Methodology: Based on 4,494 planning decisions classified as rear extensions in Lewisham, 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 Lewisham Council's public planning portal. Full methodology →
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