Free planning check
Free Harrow planning permission check
Check in 23 seconds whether your Harrow 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.
Harrow 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 | 74% | 1,909 |
| Two-storey rear extension | 74% | 1,110 |
| Wraparound extension | 87% | 119 |
| Side extension | 72% | 499 |
| Loft conversion and dormer | 74% | 223 |
| Rooflight | 80% | 775 |
| Outbuilding and garden room | 72% | 289 |
| Porch | 82% | 130 |
| Garage conversion | 83% | 121 |
| Basement | 83% | 244 |
| Window and door | 79% | 225 |
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 Withdrawn and undecided records are excluded.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 Harrow approval rates.
Application guidance in Harrow
Harrow adopted its Local Plan 2021-2041 on 24 March 2026, replacing the earlier local plan documents. Use that plan and its policies map alongside the Residential Design Guide linked from the planning-permission page, and select the application route for the proposed work.
- Harrow immediate small-HMO Article 4 direction
- Harrow adopted Local Plan and policies maps
- Harrow Article 4 guidance and area documents
- Harrow on the Hill conservation maps and appraisals
- Harrow planning applications and residential design guidance
- Harrow adopted Local Plan 2021-2041
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.
16 Brookshill Avenue: one enforcement appeal had two different outcomes
APP/M5450/C/23/3325757 · Hardstanding allowed; extension and door refused, 29 April 2026
The inspector granted permission for front hardstanding but upheld enforcement against the side-to-rear extension and first-floor door. Earlier additions counted when assessing the original building in the Green Belt. The door’s claimed PD route also failed because unlawful building operations affected the building.
What to check: Read a split decision element by element. Separate past extension permissions did not authorise the larger wraparound structure as built. Establish the building’s lawful history and cumulative additions before relying on a fallback or PD claim.
Read the appeal decision (PDF)
Related guidance: Side extensions · Rear extensions · Lawful development certificates
9–11 Palmerston Road: parking evidence supported an amended housing scheme
P/3140/21; APP/M5450/W/22/3306081 · Section 73 appeal allowed with conditions, 25 September 2023
The appeal varied plans for an already permitted 187-home mixed-use scheme, including reducing parking from 71 to 33 spaces. The inspector considered strong public-transport accessibility, a parking survey and secured obligations, finding no substantiated harm from the parking reduction.
What to check: Support changes with site-specific transport evidence and check the continuing conditions and obligations. This was a variation of an existing major permission, not a fresh unrestricted approval or a parking standard for every small housing site.
Read the appeal decision (PDF)
Related guidance: New-build planning permission
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.
- PL/0165/25 · Recorded refused (2025)
Single storey rear extension, Alterations to roof to form covered hall at rear, External alterations (Demolition of summer house)
Open the council record for PL/0165/25 - PL/0440/25 · Recorded approved (2025)
Detached single storey outbuilding at rear for use as Gym/Office
Open the council record for PL/0440/25
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.
Harrow 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 Harrow
Do I need planning permission for my project in Harrow?
Some house extensions, loft conversions and outbuildings can use permitted development rights in Harrow, 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 Harrow?
It depends on the project type. 74% of 1,909 decided single-storey rear extension applications in Harrow were approved. 74% of 223 decided loft conversion and dormer 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. Every project type is on the Harrow 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.