Side extensions in Harrow
2,963 applications since 2022. 1,872 approved and 748 refused. Refused: about 1 in 4 here, about 1 in 7 across the councils we cover.
Last updated 9 November 2026.
Without planning permission
- Single storey, no higher than 4 m
- No wider than half the width of the original house
- Not facing a road
England, houses only. Flats, listed buildings, conservation areas and Article 4 directions change this. The full rules.
Year by year
| Year | Applications | Approved | Refused |
|---|---|---|---|
| 2026 | 419 | 217 | 81 |
| 2025 | 589 | 414 | 127 |
| 2024 | 618 | 417 | 164 |
| 2023 | 565 | 316 | 145 |
| 2022 | 772 | 508 | 231 |
Neighbouring councils
| Council | Approved | Refused | How often |
|---|---|---|---|
| Barnet | 9,447 | 2,020 | about 1 in 6 |
| Brent | 4,513 | 1,385 | about 1 in 4 |
| Ealing | 16,200 | 4,787 | about 1 in 4 |
| Hertsmere | 2,482 | 397 | about 1 in 7 |
| Hillingdon | 23,367 | 7,232 | about 1 in 4 |