How Long Does Planning Permission Take in London?
Decision times for 17,907 householder applications, borough by borough, September 2025 to August 2026.
A householder planning application in London took a median of 8.0 weeks from validation to decision between September 2025 and August 2026, in line with the statutory 8-week target. 66% of decisions came within 8 weeks and 85% within 12 weeks, but 8% took longer than 16. Redbridge was the fastest borough (6.7 weeks) and Westminster the slowest (11.5 weeks).
These figures come from our 2026 London planning approvals study, which analysed every householder planning decision published on the Greater London Authority's Planning London Datahub for the 27 boroughs whose data passed our checks. The weeks are measured from the date the council validated the application to the date of the decision.
Planning decision times by borough
Boroughs are listed from fastest to slowest median. "Within 8 weeks" is the share of decisions made no more than 56 days after validation.
| Borough | Median weeks | Within 8 weeks | Decisions | Approved |
|---|---|---|---|---|
| Redbridge | 6.7 | 76% | 790 | 83.4% |
| Enfield | 7.1 | 90% | 899 | 83.0% |
| Barking and Dagenham | 7.4 | 84% | 360 | 69.2% |
| Southwark | 7.4 | 76% | 520 | 95.0% |
| Sutton | 7.9 | 90% | 565 | 90.8% |
| Waltham Forest | 7.9 | 78% | 741 | 79.9% |
| Croydon | 7.9 | 65% | 754 | 85.1% |
| Newham | 7.9 | 60% | 411 | 84.5% |
| Kingston upon Thames | 8.0 | 88% | 655 | 86.6% |
| Bexley | 8.0 | 86% | 740 | 95.1% |
| Barnet | 8.0 | 79% | 1,278 | 79.2% |
| Greenwich | 8.0 | 74% | 604 | 77.5% |
| Harrow | 8.0 | 72% | 867 | 81.9% |
| Lewisham | 8.0 | 67% | 582 | 89.2% |
| Wandsworth | 8.0 | 61% | 981 | 91.5% |
| Hillingdon | 8.0 | 56% | 1,101 | 89.9% |
| Hounslow | 8.0 | 56% | 707 | 78.5% |
| Lambeth | 8.0 | 56% | 536 | 83.4% |
| Tower Hamlets | 8.0 | 55% | 202 | 91.6% |
| Hackney | 8.0 | 55% | 427 | 83.1% |
| Havering | 8.0 | 55% | 873 | 89.0% |
| Haringey | 8.0 | 53% | 597 | 90.3% |
| Islington | 8.3 | 48% | 311 | 91.0% |
| Ealing | 8.9 | 43% | 929 | 86.4% |
| Camden | 9.1 | 42% | 402 | 87.6% |
| Merton | 9.7 | 37% | 613 | 92.5% |
| Westminster | 11.5 | 36% | 462 | 83.1% |
Brent, Bromley, Hammersmith and Fulham, Kensington and Chelsea, Richmond upon Thames and the City of London are not listed because their data feed had gaps in the period. Islington, Merton, Redbridge and Westminster are each missing one or two months, so their counts are lower than their true totals.
Lofts, extensions, basements and certificates
Most types of householder application were decided in a median of 8 weeks. Applications that included a basement took longer, and the two routes that avoid a full planning application were quicker.
| Application | Median weeks | Decisions |
|---|---|---|
| All householder applications | 8.0 | 17,918 |
| Loft conversions (planning application) | 8.0 | 4,055 |
| Rear extensions | 8.0 | 9,167 |
| Side and infill extensions | 8.0 | 5,785 |
| Wraparound extensions | 8.0 | 2,890 |
| Two-storey extensions | 8.0 | 2,235 |
| Basements | 10.0 | 506 |
| Loft lawful development certificates | 7.3 | 4,227 |
| Larger home extension prior approval | 5.3 | 2,842 |
One application can include several kinds of work, so the rows overlap. A lawful development certificate confirms that work is permitted development and is not a planning permission; our permitted development guide explains when you can use one.
What the 8 weeks does and does not include
The statutory determination period for a householder planning application is 8 weeks from the date the council validates it. Validation comes first: the council checks that the forms, drawings and fee are complete before the clock starts, and an incomplete application goes back for more information.
The figures above run from validation to decision and include any extension of time the council agreed with the applicant. Across London, 66% of decisions came within 8 weeks, 85% within 12 weeks and 92% within 16 weeks.
How planning fits into the whole project
Planning is one stage of the preparation. On our published timelines, design, planning permission and building regulations approval typically add 3–6 months before work starts on site, and a single-storey rear extension then takes 12–16 weeks on site. Our guide to how long a house extension takes sets out every stage, and our planning permission guide covers when you need to apply.
You can reduce the risk of a slow decision by submitting a complete application first time and by using your council's pre-application advice service to understand what it expects before you apply.
Planning an extension or loft conversion?
From drawings and planning to the finished build
Our in-house architectural team prepares the drawings and manages the planning application; we then build on a JCT contract, and every job carries our 10-year workmanship warranty.
Book a Consultation See the full planning studyCHAS Elite · Constructionline Gold · FMB member · 5.0 on Google
How these figures were produced
The data is every householder planning decision dated 1 September 2025 to 31 August 2026 published on the Planning London Datahub, the Greater London Authority's feed of planning applications from London's councils. Decision times are the days between the validation date and the decision date; 17,907 approvals and refusals had both dates recorded. Withdrawn applications are not counted. The full method, limitations and a downloadable CSV are in our London planning approvals study.
Frequently Asked Questions
How long does planning permission take for an extension in London?
Between September 2025 and August 2026 the median London householder decision took 8.0 weeks from validation, the statutory target. 66% of decisions were made within 8 weeks and 85% within 12 weeks. Allow longer in a conservation area or if the design needs amending.
Which London borough decides planning applications fastest?
Redbridge, with a median of 6.7 weeks from validation to decision between September 2025 and August 2026. Westminster was the slowest of the 27 boroughs we could measure, at 11.5 weeks.
How long does a lawful development certificate take in London?
Lawful development certificates for loft conversions took a median of 7.3 weeks from validation between September 2025 and August 2026, and 90.6% were granted.
Does the 8 weeks start when I submit the application?
No. The 8-week statutory period runs from the date the council validates the application, so time spent checking and validating it comes first. The weeks in this article are also measured from validation.
Do basement applications take longer?
Yes. Householder applications that included a basement took a median of 10.0 weeks from validation between September 2025 and August 2026, against 8.0 weeks for householder applications as a whole.