Rear extensions are the bread and butter of UK planning — and one of the most common reasons homeowners face a refusal. Here's what 10,512 real decisions tell us about rear extension outcomes in Harrow.
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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 | Decisions | Approved | Rate |
|---|---|---|---|---|
| 1 | Headstone | 8 | 7 | 87.5% |
| 2 | Pinner South | 13 | 11 | 84.6% |
| 3 | Kenton East | 5 | 4 | 80.0% |
| 4 | Harrow Weald | 6 | 4 | 66.7% |
| 5 | North Harrow | 8 | 5 | 62.5% |
| 6 | Edgware | 5 | 3 | 60.0% |
| 7 | Pinner | 5 | 3 | 60.0% |
| 8 | Roxeth | 5 | 3 | 60.0% |
A rear extension has a 87.5% approval rate in Headstone but just 60.0% in Roxeth.
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Not all applications are treated equally. Here's how rear extensions stack up against other common projects in Harrow.
| Type | Decisions | Rate |
|---|---|---|
| Hip-to-Gable Conversion | 66 | 86.4% |
| Conservatory | 582 | 81.1% |
| Outbuilding | 1,769 | 79.0% |
| New Build | 61 | 78.7% |
| Front Extension | 1,890 | 77.4% |
| Extension (General) | 908 | 77.1% |
| Garage / Parking | 3,654 | 76.3% |
| Wraparound Extension | 286 | 75.5% |
| Rear Extension | 10,512 | 75.3% |
| Dormer | 4,257 | 74.6% |
| Side Extension | 4,224 | 73.6% |
| Loft Conversion | 117 | 70.1% |
| Basement | 267 | 69.7% |
| Change of Use (Residential) | 739 | 63.5% |
| Flat Conversion | 274 | 63.1% |
| HMO | 287 | 56.4% |
| Annex | 76 | 42.1% |
2,601 rear extension applications in Harrow 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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