Which London Councils Decide Your Extension Fastest? 24,000 Householder Applications, Ranked by Borough
By Anderson & the LCCL Construction Team | Finchley N3
Finchley, 6 November 2026. A householder planning application — the form a homeowner submits for an extension, a loft, a porch or a garden room — has a statutory decision period of eight weeks. Every council in England reports to the Ministry of Housing, Communities and Local Government how many it decided, how many it granted and how long each took, and the ministry publishes the figures by district every quarter. The latest set, released on 24 September 2026, covers the year to 30 June 2026. We downloaded the open data and ranked every London borough and every Hertfordshire district on it.
As LABC Building Excellence Award Winners 2024 for Best Residential Extension in London — and London Regional Winner 2026 for Best Conversion or Alteration to an Existing Home — we submit householder applications to most of these councils in a normal year, so we had our own impressions of which are quick and which are not. The numbers confirmed some of them and overturned others.
What the data is, and what it is not
The figures come from the ministry's PS2 district return, the quarterly form every local planning authority files. We used the four quarters from July 2025 to June 2026 and the category the return calls householder developments. For each council we calculated three things. The official on-time rate: the share of decisions made within eight weeks or within a longer period the applicant agreed to in writing — this is the measure the government uses to judge councils, with 70 per cent over two years the floor below which a council can be designated. The extension share: the proportion of householder decisions that were made under one of those agreed extensions rather than inside the eight weeks. And the approval rate: the share of decisions that were grants rather than refusals.
Two things the data does not tell you. It does not give the average number of weeks an application took, only which time band each decision fell into, so a council that decides everything in week nine looks the same as one that decides everything in week twenty-five unless the bands separate them. And an extension of time is not a failing in itself — most are agreed because the officer wants a drawing changed rather than refused, which is often in the applicant's interest. What the extension share does show is how much of a council's on-time figure is earned inside the statutory eight weeks and how much is agreed afterwards.
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London: the headline
London's 32 boroughs decided 23,973 householder applications in the year to June 2026 and granted 86 per cent of them. On the official measure, 93 per cent were decided on time — exactly the England figure. Underneath that average the boroughs spread from 100 per cent to 78 per cent on time, from 1 per cent to 65 per cent of decisions needing an agreed extension, and from 66 per cent to 98 per cent approved.
The fastest boroughs
Bexley — 877 decisions, 99 per cent on time, only 14 per cent under an agreed extension, 95 per cent approved. The best combination of speed and approval in London.
Richmond upon Thames — 1,302 decisions (the third-busiest borough for householder work), 98 per cent on time, 28 per cent extensions, 83 per cent approved.
Barking and Dagenham — 388 decisions, every one on time, 10 per cent extensions. The catch: it refused 34 per cent of them, the highest refusal rate in London by a distance.
Havering and Hounslow — both 98 per cent on time, but with 42 and 43 per cent of decisions under agreed extensions.
Barnet — the second-busiest householder authority in London with 1,361 decisions, 95 per cent on time with only 17 per cent extensions, 80 per cent approved. For a borough of its size that is a strong record, and it matches our experience from Finchley.
Enfield — 934 decisions, 92 per cent on time with just 1 per cent under agreed extensions: nearly every Enfield decision that counts as on time was made inside the statutory eight weeks, the lowest extension share of any council in the table.
The slowest boroughs
Camden — 394 decisions, 78 per cent on time, the lowest in London. 61 householder applications — 29 per cent of the ones decided without an agreed extension — took more than 26 weeks: half a year for an extension or a loft. Approval rate 89 per cent, so the delay is not the sign of a strict council; it is a slow one.
Westminster — 366 decisions, 79 per cent on time; 23 per cent of non-extended decisions took more than 13 weeks. 82 per cent approved.
Hammersmith and Fulham — 80 per cent on time, and 65 per cent of all householder decisions were made under an agreed extension, the highest share anywhere in London or Hertfordshire. It also approved 98 per cent, the highest approval rate in the table. Read together: the council gets almost everyone to a yes, but rarely inside eight weeks.
Merton — 85 per cent on time, 47 per cent extensions; only 75 per cent of the non-extended cases were decided inside eight weeks.
Bromley — the single busiest householder authority in the table at 1,609 decisions, 89 per cent on time, 79 per cent approved, 41 decisions beyond 13 weeks.
The extension-of-time boroughs
Several boroughs post a good on-time figure that is mostly agreed rather than statutory. Islington is 99 per cent on time with 57 per cent of decisions under an agreed extension; Ealing 95 per cent and 55 per cent; Kensington and Chelsea 92 per cent and 59 per cent; Tower Hamlets 96 per cent and 43 per cent; Lambeth, Haringey and Hillingdon each around 41 per cent. If you apply in these boroughs, the realistic planning period is not eight weeks; it is eight weeks plus the extension the officer will ask you to sign, and the data says most applicants sign one.
Hertfordshire
The ten Hertfordshire districts decided about 5,100 householder applications in the year. Three Rivers (98 per cent on time, 18 per cent extensions, 91 per cent approved) and Welwyn Hatfield (95 per cent on time) lead; East Hertfordshire, Watford and Broxbourne sit at 93 to 94 per cent. St Albans — which covers Harpenden — is 92 per cent on time but with 64 per cent of decisions under an agreed extension, the second-highest share in the table after Hammersmith and Fulham, and 36 householder decisions took more than 13 weeks without one. Dacorum is 84 per cent on time with almost no extensions (6 per cent), which means its delays are plain delays. Hertsmere, which covers Borehamwood, is 91 per cent on time and 46 per cent extensions.
Approval rates: who says yes
Across London 86 per cent of householder applications were granted; across England, 90 per cent. The most generous councils were Hammersmith and Fulham (98 per cent), Stevenage (96), Bexley and Southwark (95 each), Kensington and Chelsea, North Hertfordshire and Broxbourne (94 each). The least were Barking and Dagenham (66 per cent), Greenwich (77), Hounslow and Bromley (79 each), and Barnet and Watford (80 each). A low approval rate is not a verdict on a council: it reflects what is submitted as much as how it is judged, and a borough that receives a lot of applications drawn without professional help will refuse more of them. The number to watch is your own drawings, not the borough's average.
What this means if you are applying
Plan for the real period, not the statutory one. In Bexley, Richmond, Barnet, Enfield or Three Rivers, eight weeks is a fair expectation and the data backs it. In Camden, Westminster, Hammersmith and Fulham, Merton or St Albans, budget three to six months from submission to decision, and in Camden be prepared for longer. Where the extension share is high, ask the case officer at week five whether an extension is coming and what change would avoid it; a revised drawing in week six is quicker than a refusal in week eight and a resubmission. And for the parts of a project that are permitted development — most rear extensions on a semi, most hip-to-gable and dormer lofts outside conservation areas — the planning application is not needed at all; a Lawful Development Certificate takes the same eight weeks on paper but does not depend on an officer's judgement, and a council cannot refuse one that meets the rules.
Anderson's advice
The borough matters less than the pre-application conversation. Our team has found Wandsworth's pre-application advice more useful than Islington's, and the data shows why: Wandsworth decides 91 per cent of non-extended householder cases inside eight weeks because the officer has usually already told you what will pass, while Islington's 99 per cent on-time figure is 57 per cent agreed extensions. Pay the pre-app fee in any borough with a high extension share. It costs less than a month of scaffold hire sitting idle, and the council has the final say either way.
What our clients say
“used LCCL construction for my loft conversion. Very happy with the works, arranged everything from planning to finish. completed on time with no hassle.”
— Brian Edwards, Google Reviews
Method and sources
Source: Ministry of Housing, Communities and Local Government, Planning applications in England: April to June 2026, district planning application statistics (PS2 open data, last four quarters to 30 June 2026), published 24 September 2026 and updated 29 October 2026. We summed the four quarters for each local planning authority for the householder developments category. On time = decided within eight weeks, or within an agreed extended period, as a share of all decisions. Extension share = decisions made under an agreed extension as a share of all decisions. Approval rate = granted as a share of granted plus refused. The City of London and the development corporations are excluded. All figures are our own calculation from the published return and may differ slightly from the ministry's rounded tables; the data is a count of decisions, not a measure of the time each one took.
Frequently asked questions
How long does planning permission for an extension take in London?
The statutory period for a householder application is eight weeks. In the year to June 2026, 93 per cent of London householder decisions were made within eight weeks or an agreed extension, but the realistic period varies from borough to borough: Bexley, Richmond, Barnet and Enfield decide most inside eight weeks, while Camden, Westminster and Hammersmith and Fulham frequently take three to six months.
Which London borough refuses the most extensions?
Barking and Dagenham refused 34 per cent of householder applications in the year to June 2026, the highest rate in London; Greenwich (23 per cent), Hounslow and Bromley (21 per cent each) and Barnet and Watford (20 per cent each) follow. The London average was 14 per cent and the England average 10 per cent.
Can I avoid the planning application altogether?
Often, yes. Rear extensions within the permitted development limits, and most dormer and hip-to-gable lofts outside conservation areas, do not need a planning application; a Lawful Development Certificate confirms the position in writing. Our Planning check reads the conservation-area, Article 4 and listed-building data for your postcode and tells you which parts of a project are permitted development; the council has the final say on any application.
Check your own project
Not sure whether your project needs planning permission? Enter your postcode and tick what you want to build — about two minutes, free, and the from-price for each part that qualifies appears on screen and in your inbox.
To talk through a planning application in any of these boroughs, book a free 30-minute consultation call with LCCL Construction on 020 8037 7332, or get an instant estimate in about two minutes.
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