Side extensions in Dacorum
12,593 applications since 1989. 10,798 approved and 268 refused. Refused: about 1 in 41 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 | 175 | 124 | 14 |
| 2025 | 262 | 217 | 29 |
| 2024 | 292 | 236 | 36 |
| 2023 | 346 | 271 | 39 |
| 2022 | 389 | 332 | 24 |
| 2021 | 499 | 419 | 33 |
| 2020 | 371 | 321 | 27 |
| 2019 | 369 | 333 | 14 |
| 2018 | 378 | 340 | 24 |
| 2017 | 368 | 345 | 13 |
| 2016 | 469 | 436 | 15 |
| 2015 | 422 | 383 | 0 |
Architects and agents, last 5 years
| Firm | Approved | Decided |
|---|---|---|
| Miramar Design Ltd | 51 | 53 |
| Blackwood Architects Ltd | 43 | 46 |
| Domestic Designs Ltd | 26 | 28 |
| Thompson Bradford Architects Ltd | 26 | 27 |
| Prestige Projects Management Ltd | 16 | 17 |
| Aubrey Technical Services | 13 | 14 |
| Battram Associates | 12 | 13 |
| Architects Corporation Ltd | 12 | 12 |
| Pinchin Architects Ltd. | 12 | 12 |
| GG Architecture | 11 | 11 |