Free planning check
Free Hillingdon planning permission check
Check in 23 seconds whether your Hillingdon project needs planning permission, and what the council has approved near you. Phase 1 planning drawings: standard rear or side extensions from £995 and loft conversions from £1,495, paid only when the council approves. Council and Portal fees are paid separately at submission.
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.
Hillingdon approval rates by project type
Historical approval rates in our archive, grouped by project type. These describe recorded decisions, not the chance of approval for your proposal. 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.
| Project type | Approval rate | Decided |
|---|---|---|
| Single-storey rear extension | 83% | 7,240 |
| Two-storey rear extension | 66% | 2,756 |
| Wraparound extension | 79% | 844 |
| Side extension | 71% | 1,686 |
| Loft conversion and dormer | 74% | 585 |
| Rooflight | 89% | 2,768 |
| Outbuilding and garden room | 81% | 1,230 |
| Porch | 75% | 374 |
| Garage conversion | 89% | 425 |
| Basement | 86% | 432 |
| Window and door | 86% | 496 |
A rate is only shown where at least 8 applications of that type were decided; smaller samples are shown as unknown. Withdrawn and undecided records are excluded. These figures cover all recorded years, including records without a year. Full Hillingdon approval rates.
Application guidance in Hillingdon
Hillingdon's Local Plan is split between Part 1 strategic policies and Part 2 development management policies, allocations and maps. Use the application validation checklist alongside the relevant policies and conservation guidance, rather than relying on an older draft document found in search results.
- Hillingdon Article 4 directions
- Hillingdon conservation areas
- Hillingdon application and validation guidance
- Hillingdon Local Plan and policies map
Sources reviewed . Check the source maps, wording and effective dates against your property and proposed work.
What reviewed local decisions show
These examples use official planning records. Each identifies the decision date and links to the evidence reviewed. They are not Planning Approvals projects or a prediction for another property.
5 Paras Villa: the appeal allowed only the separable ground-floor works
53203/APP/2024/63 · APP/R5510/D/24/3346385 · Split appeal decision, 13 November 2024
The inspector granted conditional permission for the rear extension and garage conversion but dismissed the first-floor side extension. Building over the garage would close an important visual gap and obscure trees within Harefield Village Conservation Area.
What to check: Read which elements a decision actually allows. The ground-floor works were physically and functionally separable; their approval did not authorise the upper extension or confirm permitted development rights.
Read the appeal decision (PDF)
Related guidance: Garage conversions · Side extensions
Check the planning register for the issued notice, exact conditions and any later appeal or revised application. A committee resolution is not a substitute for those documents.
Application records to compare
Selected archive records, not a representative sample or a prediction for your address. The descriptions below are archive excerpts and may be shortened; read the original decision and plans before relying on them.
- 10000/APP/2026/168 · Recorded approved (2026)
Erection of a single storey extension to the rear
Open the council record for 10000/APP/2026/168 - 10063/APP/2026/80 · Recorded approved (2026)
Conversion of part attached side garage into habitable use, erection of single storey rear extension, and amendments to fenestrations.
Open the council record for 10063/APP/2026/80
Compare the property type, works and application route. A scheme involving flats or several alterations is not directly comparable to a simple house extension. Read the archive's coverage and limitations.
Hillingdon planning resources
Check the authority's current records for the property's planning history, application requirements and local restrictions.
Prepare for your planning application
Questions about planning in Hillingdon
Do I need planning permission for my project in Hillingdon?
Some house extensions, loft conversions and outbuildings can use permitted development rights in Hillingdon, but size alone does not establish eligibility. Check the property type, previous extensions, planning conditions and the rules for the proposed work. Householder rights do not apply to flats. Conservation areas and Article 4 directions restrict particular rights; they do not automatically require an application for every change. Listed building consent is a separate requirement for works affecting a listed building's special interest.
What is the planning approval rate in Hillingdon?
It depends on the project type. 83% of 7,240 decided single-storey rear extension applications in Hillingdon were approved. 74% of 585 decided loft conversion and dormer 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. Every project type is on the Hillingdon approval rates page.
Read the official guidance on when permission is required, listed buildings and conservation areas and planning decision periods.
Approval rates are computed from 2,343,419 decided applications across 181 councils, published by each council. The free check is guidance from the public record, not a council decision.