Evidence/London Small Sites/Harrow

Harrow

Small residential planning decisions from January 2023 onwards, coded from the council’s own register to the same method used in all 33 London planning authorities.

495 applications · 361 decided · 48% approved Data to Apr 2026 Release August 2026

Applications logged

495

Full, householder and minor resi since Mar 2023

Decided so far

361

173 approved, 188 refused, 41 withdrawn

Approval rate

48%

Under half of decided applications

Typical time to decide

8 weeks

Median determination time across all small sites

Harrow, area by area

Colour shows how often applications get approved. Numbers show how many were decided. Hover or tap an area for detail.

Spotlight

Harrow Town

Decisions

Approved

Refused

Approval rate

45%

Hover or tap any tile to see that area’s detail.

Tile positions are schematic, not to geographic scale. Each hex represents one of Harrow’s sub-areas as defined in the council’s own planning framework.

Stanmore approves 58% of applications. Harrow Weald, closer to 29%. Same borough, same policy, 29 percentage points of difference.

Which kinds of schemes get approved?

Bar length shows how many of each type were decided. The split shows the share approved versus refused. Conversion is by far the most common route in Harrow, but it's extension that sees the highest approval rate.

Approved Refused Bar length = sample size (max n=192)

Conversion

49%n=192

Demolish & rebuild

45%n=67

End-of-terrace

33%n=43

Extension

82%n=28

Scheme types with fewer than 10 decisions in the window are not shown here.

Conversion, dividing one home into flats

Demolish & rebuild, existing building replaced with new homes

End-of-terrace, new infill at the end of a terraced row

Extension, rear, side or upward additions creating a new unit

Why applications fail in Harrow

Of every hundred reasons cited in refused decisions in Harrow, space standards accounts for the biggest slice at 35%.

Space 35%

Design 20%

Other 15%

Space standards, unit and room sizes, ceiling heights, private outdoor space 35

Design quality, bulk, massing, appearance, materials 20

Other, mixed or uncategorised reasons 15

Transport and parking, parking, highway safety, cycle storage 7

Neighbour amenity, overlooking, loss of light, privacy, noise 6

Policy, land use, affordable housing, principle of development 6

Insufficient information, missing reports, surveys or assessments 4

Flood risk 3

Permitted development, prior approval conditions not met 1

Infrastructure, drainage, energy, biodiversity 1

Read as: “Of every 100 reasons cited in a refusal, 35 relate to space standards.” A single refusal often names two or more reasons. Based on 412 reasons extracted from refused decision notices.

In Harrow, the most common ground for refusal is space standards.

Is Harrow getting busier?

Decisions per quarter have held roughly steady since 2023, and approval rates have edged down over the same window.

Decisions per quarter

Approval rate (%)

Hover any bar or dot for exact quarterly values. The most recent quarter may be partial while pending decisions work through.

Interrogate the data yourself

Every figure on this page comes from Harrow's own planning decisions. We publish the underlying data so you can check it, replicate our findings, or use it in your own tools. Verify against the council's planning portal before relying on any record, and tell us if you spot a problem.

Download the data (Excel) CSV

Decided small-site applications, 1 to 9 units. Planning-decision layer only: Energy Performance Certificate, Land Registry and case-officer fields are held back. Contains public sector information licensed under the Open Government Licence v3.0. Source: Planning London Datahub, Greater London Authority. Method.

About these figures

The figures describe decided applications for one to nine homes. They show what has happened in Harrow over the period covered; they do not predict the outcome of an individual application, and no approval probability is offered for any site or scheme.

Sample sizes are shown with the findings. Where the available evidence is too thin for a result to carry meaning, it is withheld or marked accordingly.

Method Current release Compare other boroughs

Research using this evidence

Briefing Harrow’s 2026 local plan: the small-site exemption survives
Research Given what you received: the outcome differential — Harrow’s mix-adjusted differential is −3.2 points.

All research →

Data sources & method

Applications. Sourced from the Greater London Authority (GLA) Planning Datahub and Harrow Council’s online planning register. Covers full planning, householder, and minor residential applications of nine units or fewer decided in the window shown above.

Decisions and timing. Outcomes and determination times are taken from the council’s published decision notices.

Refusal reasons. Extracted from refused decision notices that were publicly available. Not every refusal has a readable notice, so totals count all refusals but the reason breakdown covers only those we could read.

Scheme classification. Site types (conversion, demolish & rebuild, extension, and so on) are coded from application descriptions and drawings. Areas are mapped from postcodes and ward names using the council’s own sub-area definitions.

Update frequency. Refreshed quarterly. Next refresh: October 2026.

Nothing here is planning advice. Outcomes are historical and do not predict individual cases. Approval rates vary with site specifics, policy context, and case officer. See our Terms of Use for full details on how this data is compiled and the limits of its use.