Methodology
Where Planning Decoder’s intelligence comes from.
Every Site Intelligence Report is built from official UK public data sources. No scraping of private databases, no invented findings, no recycled templates. This page lists exactly what we query and what we’ve extracted to date.
Beta · independent research service. Planning Decoder is not a regulated planning consultancy. We aggregate public data and surface patterns. For formal applications, always engage a member of the Royal Town Planning Institute (RTPI). Figures below are updated as our coverage grows.
Planning applications & decisions
Idox public-access portals · 207 authorities
The most common planning-portal platform in England. We query weekly lists, decision notices, officer reports, consultee responses and document bundles. Blocked portals are flagged in the postcode checker.
Council weekly planning lists · 119+ weeks per council
Many councils publish full weekly lists as PDFs via parish or community councils. We parse these directly with PyMuPDF to surface applications that never appear in portal search results.
Planning Inspectorate decisions (PINS)
Appeal decisions under Section 78 (planning), Section 174 (enforcement), CLEUD, and listed buildings. Full decision text, inspector reasoning, paragraph-level analysis.
Local Review Body records (Scotland)
Councillor voting records, motions, minutes of appeal deliberations. Retrievable per case where published.
Pre-application registers
Where councils publish pre-application advice, we surface officer positions given in writing before any formal application.
Policy & framework
National planning frameworks
NPPF (England), NPF4 (Scotland), Planning Policy Wales / NDF, plus all accompanying technical advice notes and guidance.
Local plans, supplementary guidance, SPGs
Authority-specific development plans, housing-in-the-countryside policies, AONB-specific SPGs, ribbon development and infill criteria, rural worker dwelling policies.
Counterparty & case context
Companies House register
Named-entity search on sites, applicants, agents and interested parties. Cross-reference of trading status, director history, dissolution dates, filing gaps.
Parish and community council minutes
Formal objections, asbestos and safety concerns, Ombudsman references, neighbour-view assessments. Often not retrievable via standard portal search.
Local Government Ombudsman records
Where a prior Ombudsman investigation exists, the outcome can be highly material to legitimate expectation arguments.
Mapping & historic
ONS boundary files & GSS codes
Canonical identifiers for every UK local authority, ward and constituency. We key reports to GSS codes rather than authority names for stability across council reorganisations.
Welsh historic mapping (National Library of Wales)
Late 19th and early 20th century OS surveys. Free, public, decisive for Replacement Dwelling arguments where a lawful prior structure is in question.
Ordnance Survey Open Data
Boundary data, land use classifications, current mapping context.
Valuation Office records
Referenced for lawful-use history where planning-register evidence is incomplete.
Scraped & derived datasets
PlanningGeek.co.uk · full archive
UK planning case-law and commentary archive, extracted for comparable-decision research.
RAG knowledge base · 496 rows
Curated planning-law knowledge indexed for the chatbot and report generation.
Reddit public planning discussions
Selected threads from r/Planning, r/HousingUK and r/LegalAdviceUK indexed for common-question patterns and client language.
How we verify
Every claim in a Site Intelligence Report traces back to one of the sources above. We quote verbatim where the exact wording matters (refusal grounds, officer statements, councillor motions). We paraphrase where it doesn’t. We don’t invent findings, and we don’t recycle templates — each report is assembled from the specific records available for that site.
Where we can’t confirm something, we say so. Where an authority doesn’t publish the data we’d need, we flag it. Every report ends with the methodology section listing exactly what was queried for that specific site.
What we can’t find
Honest limits on coverage:
- Some Idox portals are IP-blocked to automated access — we serve an amber council_blocked result in the postcode checker when this happens, and switch to manual retrieval for paid reports.
- Not every council publishes weekly lists or pre-application decisions publicly. Where they don’t, we rely on the portal only.
- Committee minutes are patchy outside the major authorities — we rely on portal officer reports as the substitute.
- Historic mapping coverage is strongest for Wales (via Cynefin) and weaker for parts of England and Scotland.
- We do not access private registers, unpublished council correspondence, or any data not available to the public.