Outbuilding and garden room planning approval rate in Harrow
72% of 289 decided outbuilding and garden room applications in Harrow were approved.
Checked against 20.6 million UK planning applications on file across 420 planning authorities. Approval rates from 2,343,419 decisions we classified across 181 councils in England.
A similar project nearby can help you understand the council's decisions. Its outcome does not establish what will be acceptable at your address.
72%
Approval rate, all years, from 289 decided
289
decided outbuilding and garden room applications in Harrow: 208 approved, 81 refused
71%
Recent rate, decided since 2022, from 234 decided
How to read these rates
These are historical outcomes for the applications in our archive, not the chance of approval for your property. Compare the same project type and read the decided count alongside each percentage.
About the planning data
Rate = approved divided by approved plus refused, using the decisions in our classified archive. Rates are withheld as unknown where fewer than 8 records of that project type were decided. Withdrawn applications are excluded.
Recent means records dated 2022 or later. Records without a year are excluded from the recent rate but remain in the all-years figure. Historical coverage varies by council, and duplicate application references may remain in the archive.
Approval rates from 2,343,419 decisions we classified across 181 councils in England. The wider 20.6 million application catalogue is accessible through PlanIT; it is not the dataset used to calculate these percentages.
Read the full methodology and coverage notes.
Project types and outcomes are classified from council records. Check the original application and decision notice before relying on an individual example. A page rebuild does not mean every council record has just been refreshed.
Example outbuilding and garden room decisions in Harrow
These examples deliberately include approved and refused applications where available. They are not a representative sample or a list of the latest decisions. Look up each reference on the council's planning search to read the plans and decision notice.
| Reference | Year | Decision | Application |
|---|---|---|---|
| PL/0809/25 | 2025 | Approved | Detached single storey outbuilding at front to be used as a three car garage (Demolition of outbuildings to front Pinewood House |
| PL/2892/25 | 2025 | Approved | Certificate of Lawful Development Proposed: Detached Outbuilding at rear for use as Gym/Home Office Brookslee |
| P/2265/23 | 2024 | Approved | Use of outbuilding as self-contained annexe incidental to main dwelling |
| PL/0253/23 | 2024 | Refused | Proposed outbuilding in rear garden (retrospective). |
| PL/0686/23 | 2024 | Refused | Detached outbuilding in rear garden for use as self contained annexe incidental to main dwelling house |
| P/0038/23 | 2023 | Refused | CERTIFICATE OF LAWFUL DEVELOPMENT (PROPOSED): Detached outbuilding at rear for use as Gym |
About the planning data
Checked against 20.6 million UK planning applications on file across 420 planning authorities. Approval rates from 2,343,419 decisions we classified across 181 councils in England.
Other project types in Harrow
- Single-storey rear extension 74%, 1,909 decided
- Two-storey rear extension 74%, 1,110 decided
- Wraparound extension 87%, 119 decided
- Side extension 72%, 499 decided
- Loft conversion and dormer 74%, 223 decided
- Rooflight 80%, 775 decided
- Porch 82%, 130 decided
- Garage conversion 83%, 121 decided
- Basement 83%, 244 decided
- Window and door 79%, 225 decided