London’s borough planning certainty score has been climbing for two years running, but that citywide number hides something important: a gap between boroughs big enough to change how you should think about any single site. Authority Inc’s London Borough Planning Certainty Index puts the twelve months to February 2026 at 67.6 out of 100. Put plainly, 12,044 of 17,807 fully observed applications got a favourable decision within 180 days.
If you’re weighing up a London site, the citywide figure isn’t really the number you need. What matters more is how the specific borough has been performing, and what’s shifting in policy right now that hasn’t shown up in the data yet. Here’s what the September 2026 edition, checked 1 September 2026, actually tells you.
Quick Answer
London borough planning certainty sits at 67.6 out of 100 for the trailing 12 months to February 2026, up 3.6 points on the year before. About two in three comparable applications across the 33 boroughs land a favourable decision inside 180 days. But individual boroughs swing from the low 80s down to the high 30s, a spread more than ten times bigger than that annual citywide move.
How the Score Actually Gets Built
Planning certainty tracks the share of fully observed, substantive applications that get a favourable recorded decision within 180 days of validation. That covers full planning permission, full planning with listed-building consent, and full planning with conservation-area demolition consent, applied the same way across all 33 borough authorities.
Two rules keep the number honest. Every application needs its full 180-day window to close out, and a monthly cohort only gets published once at least 80% of its cases are observable. February 2026 hits 88.6% coverage, which is why the headline data stops there even though the page itself was last checked on 1 September 2026. Anything from March 2026 onward simply hasn’t had time to mature yet.
The data comes from the Planning London Datahub, and Authority Inc says Oxford AI has reviewed its methodology against data ethics standards.
What This Number Won’t Tell You
A higher score just means favourable decisions were more common and came in on time. It says nothing about whether those approved schemes ever got financed, broken ground, or finished. Planning approval is one step in a much longer process, and everything after it, finance, legal agreements, actual construction, sits outside this index entirely.
One thing worth flagging: the pool of applications being tracked has shrunk, from 21,143 in December 2021 down to 17,807 in February 2026. Authority Inc’s own reading is that some of this drop-off might be weaker projects never getting submitted at all, which would push the score up a bit for reasons that have nothing to do with planning teams actually working faster.
What’s Behind the Improvement Since 2022
The index hovered around 59 through most of 2022 and 2023 before climbing steadily, from 59.9 in January 2024 up to 67.6 by February 2026. Isabella L.B., PhD, a senior land and development specialist at AtkinsRéalis who reviewed the data independently, doesn’t point to one clean cause. She names three.
Fewer applications coming in is her top pick. Less volume means less pressure on planning teams, and it may also mean the applications that do get submitted are stronger on average. Higher fees and tighter deadlines come next, probably producing a mix of genuinely quicker decisions alongside more negotiated extensions. Backlogs from 2022 and 2023 round it out, and she puts those down to a pile-up of policy and process changes rather than simple staff shortages.
There’s also a factor she thinks the index can’t capture on its own: the 2021 to 2026 affordable-housing funding cycle may have pushed applicants to lock in approvals and start building before the March 2026 funding deadline. That pressure would be concentrated in residential and grant-backed schemes rather than spread evenly across everything.
The Borough Numbers Are Where the Real Story Is
The gap between boroughs makes the citywide annual shift look small. Among the 29 boroughs with enough sample size and coverage to be ranked:
Doing well
- Wandsworth: 82.7 (738 applications)
- Islington: 81.7 (624 applications)
- Camden: 79.6 (751 applications)
- Southwark: 79.4 (544 applications)
- Haringey: 74.0 (611 applications)
Struggling
- Croydon: 44.7 (627 applications)
- Havering: 45.5 (369 applications)
- Harrow: 36.2 (260 applications)
Wandsworth and Harrow are 46.5 points apart. Compare that to the 3.6 point move in the London average over an entire year and you can see why the citywide figure only gets you so far. Authority Inc treats this as a useful comparison rather than a permanent league table, given some boroughs are working with sample sizes in the low hundreds. Still, the lesson holds: look at the borough’s own record before you look at London’s.
Three Policy Changes Still Working Their Way Into the Data
The Draft London Plan. City Hall kicked off a 13-week statutory consultation in mid-July 2026 covering housing, infrastructure, design, and environmental policy. Since borough local plans have to stay in general conformity with the London Plan, this is already shaping how applicants and councils think, well before it’s formally adopted.
Affordable-housing funding under review. The £11.7 billion programme running from 2026 to 2036 turned out to be significantly overbid, so City Hall asked applicants in July 2026 to revise their bids around delivery confidence and value for money. That can change which already-approved schemes stay financially viable, even if it doesn’t touch the planning-decision score directly.
New rules for housing near stations. National government announced in August 2026 that it wants to fast-track housing near train, tram, and Underground stations by giving more weight to transport access. London boroughs deal with a lot of station-area applications, so this could change what gets submitted where, though it’s too early to see any effect on approval speed.
Colliers’ Head of Planning, Anthony Aitken, has made the point that engaging early with emerging policy and site allocations can unlock development potential and support land values, which is basically why applicants are treating this consultation as something to act on now rather than wait out.
The Live Forecasts
Separate from the historical index, Authority Inc is tracking 22 unresolved named applications locked on 25 August 2026, with approval probabilities ranging from 18% to 91%. These run on different clocks than the main index, 180 days for prime residential and 365 days for hotels, and Authority Inc calls them shadow forecasts rather than validated predictions. They sit outside the headline score and don’t move it either way.
Before You Commit to a Site in London
Look at the borough, not the city. A 67.6 citywide average can be sitting right next to a 36.2 in Harrow or an 82.7 in Wandsworth. Pull the borough’s own record before you decide anything.
Keep an eye on the policy transition. The Draft London Plan, the affordable-housing funding shake-up, and the new station-area rules could all change what gets submitted before any of it shows up in a mature cohort.
Don’t confuse planning approval with delivery. Getting a favourable decision doesn’t mean a project actually gets built. Finance, legal conditions, construction, and timing are all separate risks that live outside this index.
Frequently Asked Questions
How quickly are London borough planning applications approved?
In the latest mature cohort, 12,044 of 17,807 fully observed applications got a favourable decision within 180 days, a score of 67.6 out of 100. It varies a lot by borough.
Is London planning certainty improving?
Yes, based on the measured data. The score went from 64.0 in February 2025 to 67.6 in February 2026, though Authority Inc says that improvement still needs to hold up as newer cohorts mature.
Does the index cover every planning application in London?
No. It only covers substantive full planning applications that meet specific inclusion rules. Minor and non-comparable applications are excluded so they can’t skew the number.
Does a favourable decision mean a project will actually get built?
No. Finance, construction, leasing, and delivery all happen outside this index and need to be tracked on their own.
The Takeaway
About two in three comparable London planning applications get a favourable decision within 180 days, and that rate has been improving for two years straight. But the gap between boroughs is more than ten times larger than the citywide annual move, and three policy changes are already in motion that haven’t shown up in the numbers yet.
If you’re sizing up a specific site, the borough’s own track record and a sense of where the Draft London Plan is heading will tell you far more than the London-wide average ever will.
