Side extension planning approval rate in Hillingdon
71% of 1,686 decided side extension applications in Hillingdon 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.
71%
Approval rate, all years, from 1,686 decided
1,686
decided side extension applications in Hillingdon: 1,191 approved, 495 refused
75%
Recent rate, decided since 2022, from 879 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 Withdrawn applications are excluded. The eight-record threshold is a display rule, not a guarantee that a sample is statistically reliable.
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.
Coverage for this project type
Dated records in this archive span 1993 to 2026. 0 of 1,686 decided records have no year recorded. Coverage may have gaps within the date range.
879 decided records are dated 2022 or later. This is an archive count, not a measure of all current council activity.
These project categories can include different application routes and proposals combining several kinds of work. Read the proposal and decision type before comparing it with your project.
Check planning requirements in Hillingdon, or read about permitted development in Hillingdon. An approval rate does not decide which route your property qualifies for.
Example side extension decisions in Hillingdon
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.
Search Hillingdon's planning register using the references below. Descriptions may be shortened; read the complete proposal and decision notice.
| Reference | Year | Decision | Application |
|---|---|---|---|
| 13426/APP/2025/3033 | 2026 | Refused | Variation of Condition 2 (Approved Plans) of planning permission ref. 13426/APP/2024/3060, dated 07-03-25 (Erection of a two storey extension to the side and... 1 WOODSIDE ROAD |
| 15988/APP/2025/2930 | 2026 | Approved | Erection of a part single, part double storey rear extension, double storey side extension, extension of front porch, amendments to fenestrations, conversion... 511 UXBRIDGE ROAD |
| 17031/APP/2025/2947 | 2026 | Refused | Subdivision of existing single dwellinghouse into 2 x three-bedroom houses, including the erection of a two storey extension to the side following the partia... 48 LOTHIAN AVENUE |
| 18301/APP/2025/2883 | 2026 | Refused | Erection of first floor side extension, and addition of driveway and dropped kerb to front 19 ELGOOD AVENUE |
| 18998/APP/2025/3152 | 2026 | Approved | Erection of a first floor side extension. 80 FAIRWAY AVENUE |
| 19968/APP/2025/3112 | 2026 | Approved | Erection of double storey side extension, single storey rear extension, and amendments to fenestrations. 43 CRAIG DRIVE |
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 Hillingdon
- Single-storey rear extension 83%, 7,240 decided
- Two-storey rear extension 66%, 2,756 decided
- Wraparound extension 79%, 844 decided
- Loft conversion and dormer 74%, 585 decided
- Rooflight 89%, 2,768 decided
- Outbuilding and garden room 81%, 1,230 decided
- Porch 75%, 374 decided
- Garage conversion 89%, 425 decided
- Basement 86%, 432 decided
- Window and door 86%, 496 decided