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Rear Extension Approval Rates in King's Lynn & West Norfolk

Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 149 real decisions tell us about rear extension outcomes in King's Lynn & West Norfolk.

149 real decisions·January 2020 to present·Updated March 2026
96.0%
Approval Rate
149
Decisions
143
Approved
6
Refused
96.0% approved. But 6 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.

These are council averages. Your property is specific.

Two houses on the same street can get different outcomes.
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 King's Lynn & West Norfolk.

TypeDecisionsRate
Front Extension20
100.0%
Conservatory44
100.0%
Side Extension81
100.0%
Dormer23
100.0%
Outbuilding145
97.2%
Rear Extension149
96.0%
Extension (General)376
95.5%
Garage / Parking298
91.9%
New Build86
90.7%
Annex55
85.5%
Change of Use (Residential)125
82.4%
See how this applies to your postcode →

What the data tells us

1
96.0% of rear extension applications in King's Lynn & West Norfolk get approved. That means 6 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

6 rear extension applications in King's Lynn & West Norfolk 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 King's Lynn & West Norfolk planning data

Nearby councils rear extension data

Methodology: Based on 149 planning decisions classified as rear extensions in King's Lynn & West Norfolk, 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 King's Lynn & West Norfolk Council's public planning portal. Full methodology →
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