The problem
Official statistics report that 91% of major planning applications are decided within the statutory period or an agreed extension. Measured against the statutory 13-week deadline alone, the figure is 19%. Around 71% of major applications rely on extensions of time. The headline metric systematically conceals the real one.
The measurement failures compound. The Housing Delivery Test’s latest official measurement is still 2023, published December 2024 — the mechanism that triggers presumption-in-favour sanctions is running three years stale. Only about 30% of English planning authorities have an up-to-date adopted local plan.
Meanwhile the pipeline is contracting. Planning permission was granted for 209,781 homes in the year to September 2025 — the lowest 12-month total since 2013, against roughly 370,000 a year needed to support the target. Net additional dwellings were 208,600 in 2024-25, and the government tracker records 26% of the 1.5 million target delivered with the pledge rated off track.
And 2025-26 outturn will not be published until around November 2026. The system that is meant to deliver 1.5 million homes cannot see its own current performance.
The system
Plumbline builds the honest measurement layer for the planning system, and does it in the window that MHCLG has itself created — planning data standards are due in summer 2026, with the National Infrastructure Spatial Tool entering private beta in November 2026.
It reports determination performance against statutory deadlines and against extensions separately, always both, so that the gap is visible rather than hidden. It tracks extension-of-time usage as a first-class metric, since a system where 71% of major decisions need an extension has a capacity problem the headline denies.
It maintains a live Housing Delivery Test estimate between official measurements, using permissions, starts, completions and building control data, so authorities and MHCLG can both see the trajectory rather than discovering it two years late.
And it tracks the full pipeline from allocation through permission to completion, exposing where homes are being lost — refusal, appeal, viability, or permissions granted and never built.
Worked examples
Two situations this system answers
A council reports 91% of major applications decided on time and is judged compliant. Measured against the actual statutory deadline it is 19%, because more than three-quarters used an agreed extension.
Plumbline always shows both numbers side by side, and shows how often extensions are being used to make the headline look better.
The Housing Delivery Test that triggers presumption-in-favour sanctions was last measured on data ending March 2023. Councils and the department are both flying blind on the mechanism meant to deliver 1.5 million homes.
Plumbline keeps a running estimate going between official measurements, so everyone can see where housing delivery is heading instead of finding out two years later.
Data foundation
Every dataset below is open, or its access constraint is stated
| Dataset | Publisher | What it provides |
|---|---|---|
| Planning application statistics (PS1/PS2) | MHCLG | Quarterly decisions, speed, and grant rates by authority. |
| planning.data.gov.uk | MHCLG | The emerging national planning data platform, with standards due summer 2026. |
| Housing supply: net additional dwellings | MHCLG | Annual outturn — the definitive delivery measure, published with a long lag. |
| Indicators of new supply | MHCLG | Quarterly starts and completions, the leading indicator. |
| Local Land Charges register | HM Land Registry | Digital, centralised, 127 authorities live, extending to building regulations. |
| Planning Inspectorate statistics | PINS | Appeal volumes, outcomes and decision times. |
| EPC lodgements | MHCLG | New dwelling completions with a much shorter lag than official statistics. |
| Local plan status | MHCLG / PINS | Adoption dates and plan stage by authority. |
Capabilities
Benefits
For government
- Gives MHCLG honest, current performance data on the delivery mechanism for its highest-profile housing commitment.
- Supports and tests the planning data standards MHCLG is introducing in summer 2026, providing conformance feedback from day one.
- Makes the case for planning capacity investment evidentially rather than anecdotally — 97% of planning departments reported a skills gap in the last survey, itself now three years old.
- Complements rather than duplicates the National Infrastructure Spatial Tool, which addresses infrastructure rather than housing determination performance.
For the public
- Applicants — including individual householders — can see realistic timelines for their authority rather than a misleading headline.
- Communities can see whether their council is genuinely delivering its plan or quietly missing it.
- Faster, better-resourced decisions mean homes built sooner for people who need them.
Delivery
Phasing
Risks & mitigations
Publishing the gap between headline and statutory performance is uncomfortable. It is also already implicit in published statistics — Plumbline surfaces rather than reveals it.
Smaller than it appears. The April 2026 regulations mandate local plan timetables and housing requirement figures — not planning applications. The platform’s application dataset holds records from four councils, effectively three, and its collection has not run since 17 September 2025 while every other dataset collects daily. The gap is durable, not closing.
Delay has many causes, not all within an authority’s control. Reporting separates authority-controlled from applicant-controlled and consultee-driven delay.
Sources
All sources checked in August 2026. Figures carry the reference period of their source, which may differ from publication date. Where a figure could not be verified against a primary source it is not used.