Define the question first
Each index begins with a fixed written definition: geography, eligible application types, outcome, time window and minimum evidence required.
Authority Intelligence · Data methodology
How Authority builds its market indexes
A plain-English record of what enters each index, how outcomes are scored, when a period is mature enough to publish and what the numbers do not claim.
Last updated 25 August 2026
Rules shared by every index
The publication process
Collect the full eligible public population
We use the Planning London Datahub and linked official planning records. We do not select only successful or interesting projects.
Keep one project record from becoming many outcomes
Administrative updates, consultations, condition discharges and duplicate documents are excluded or joined to the underlying application where the index rule requires it.
Give every case enough time
A case is scored only after its complete observation window. Newer cohorts are withheld rather than treated as failures.
Do not turn missing data into a negative outcome
If the public record does not establish the result, the case remains unresolved. It is not silently counted as refused or late.
Publish the denominator
Every score is accompanied by its case count, favourable count and outcome coverage where available. Small samples are clearly labelled.
Separate measurement from interpretation
The historical series measures what happened. Timeline explanations and expert commentary are labelled separately and do not alter the score.
Index-specific definitions
Exactly what each score means
London Borough Planning Certainty Index
- Scoring rule
- Count a substantive full planning application as successful when the recorded borough decision is favourable within 180 days of validation.
- Time window
- Monthly trailing 12-month validation cohorts.
- Included
- Full planning permission and specified combined full-planning consent types handled by one of London's 33 borough planning authorities.
- Publication rule
- At least 90% outcome coverage, a complete 180-day observation window and at least 100 observed cases for a borough ranking.
- Not measured
- Development corporations, Greater London Authority cases, missing outcomes, later approvals and construction delivery.
London Restaurant Planning Speed Index
- Scoring rule
- Count an eligible restaurant-related application as successful when the recorded decision is favourable within 180 days of validation.
- Time window
- Monthly trailing 12-month validation cohorts.
- Included
- Comparable full-planning cases explicitly concerning restaurants, cafés, pubs or takeaways.
- Publication rule
- At least 90% outcome coverage and a complete 180-day observation window.
- Not measured
- Openings that require no planning application, commercial performance, restaurant survival and unresolved outcomes.
London Data Centre Planning Approvals Index
- Scoring rule
- Count an eligible substantive data-centre application as successful when its recorded final planning decision is favourable.
- Time window
- Quarterly trailing 24-month decision cohorts.
- Included
- Full, outline and reserved-matters applications with a recorded final decision.
- Publication rule
- Only mature resolved cases are included; the small historical sample is always disclosed.
- Not measured
- Consultations, condition discharges, amendments, adverts, administrative records, construction, power connection and operational delivery.
Open data
Download every published series
The human-facing graph and the machine-readable files use the same source data. JSON contains index metadata; CSV provides a simple observation table.
London Borough Planning Certainty Index
The share of substantive London planning applications receiving a favourable recorded decision within 180 days.
London Restaurant Planning Speed Index
The share of comparable London restaurant, café, pub and takeaway planning applications receiving a favourable decision within 180 days.
London Data Centre Planning Approvals Index
The share of comparable, substantive London data-centre planning applications receiving a favourable planning decision.
Primary source
The current London planning indexes are derived from public Planning London Datahub records and linked borough records.
Planning London DatahubImportant limitation
These indexes measure recorded planning outcomes under fixed rules. They do not prove causation and they do not automatically measure construction or commercial delivery.