Data Methodology

Overview

PlotDetect maintains a structured database of planning provisions extracted from NSW Development Control Plans (DCPs) and Local Environmental Plans (LEPs). This page describes how that data is produced, verified, maintained, and delivered.

Source Documents

PlotDetect's primary sources are the official planning instruments published by NSW local councils and the NSW Government:

• Development Control Plans (DCPs): Detailed planning controls covering setbacks, heights, floor space ratios, heritage provisions, landscaping, parking, and site-specific requirements
• Local Environmental Plans (LEPs): Statutory instruments defining zoning, land use permissibility, heritage listings, and development standards
• State Environmental Planning Policies (SEPPs): State-level instruments including SEPP Housing 2021, SEPP Exempt and Complying Development Codes 2008, and others — sourced directly from the NSW Legislation website
• Heritage schedules and conservation area maps: Council-gazetted heritage items, heritage conservation areas, and associated provisions
• NSW Planning Portal (live): Property zoning, heritage overlays, flood and bushfire prone land, FSR and height limits, and lot geometry are queried in real time from the NSW Planning Portal spatial API at the moment of each search — not from a cached copy. This is the same authoritative spatial data used by NSW councils and the Department of Planning

All source documents are publicly available from council websites and the NSW Legislation website. PlotDetect does not use proprietary or non-public data sources for planning provisions.

Extraction Process

Planning provisions are extracted from source PDFs through a structured process:

1. Document parsing: DCP and LEP documents are parsed to identify individual provisions, their hierarchical structure (part, section, clause, sub-clause), and relationships to zones, precincts, and development types
2. Provision structuring: Each extracted provision is stored with structured metadata including:
   • Provision text (verbatim from source document)
   • Source document name and version
   • Section, clause, and sub-clause references
   • PDF page number
   • Applicable zones and land use categories
   • Applicable precincts (where spatially defined)
   • Development types the provision applies to
   • Whether the provision is a numerical standard, design guideline, or heritage-specific control
3. Spatial indexing: Precinct boundaries are digitised and stored as PostGIS geometries, enabling spatial queries that match a property location to its applicable precinct-specific provisions
4. Relationship mapping: Cross-references between provisions (e.g., "see also Section 4.3", "subject to the requirements of Part 6") are captured as structured relationships, not loose text

Automated Pathway Triage

PlotDetect performs comprehensive automated analysis of all approval pathways available for a property, presenting the fastest pathway first:

Compliance-Grade Guarantee: Pathway triage is performed using deterministic extraction from SEPP provisions, not AI interpretation. Every trigger checked, every standard verified, and every exclusion identified can be traced to its source clause and PDF page in the legislation.

Provenance Chain

Every provision in PlotDetect's database maintains a complete provenance chain:

This chain means any provision returned by PlotDetect can be independently verified by a user opening the source DCP document and navigating to the cited page and section.

Data Currency

Planning instruments are amended by councils periodically. PlotDetect tracks data currency at the council level:

• Each council's DCP has a recorded "last parsed" date, indicating when PlotDetect last extracted provisions from the current version
• When a council publishes an amended DCP, PlotDetect re-parses the updated document and flags changed, added, or removed provisions
• Data currency dates are disclosed to users so they can assess whether the data reflects the most current planning instrument

There may be a lag between when a council amends a DCP and when PlotDetect reflects the change. Users should always verify critical decisions against the current version of the source document, available from the relevant council's website.

Heritage Data

Heritage provisions receive additional structured treatment:

• Heritage item identification: Properties listed as heritage items under the LEP are identified with their item number, name, address, and significance level (local or state)
• Heritage conservation areas: Properties within heritage conservation areas (HCAs) are identified with the applicable HCA name and boundary
• Heritage-specific DCP provisions: Provisions from heritage-specific sections of DCPs are linked to the relevant heritage items and HCAs, including controls on materials, scale, setbacks, demolition, and alterations
• Provision chains: Where heritage provisions reference or modify general provisions (e.g., "despite Section 3.2, heritage items in the Haberfield HCA must..."), these override relationships are captured

Quality Assurance

• Automated validation: Extracted provisions are validated for completeness (mandatory fields populated), consistency (zone codes match LEP definitions), and referential integrity (cross-references resolve)
• Sample verification: A random sample of provisions is manually checked against source documents after each extraction run
• User feedback: Reported inaccuracies are investigated, corrected, and logged

What PlotDetect Does Not Do

• PlotDetect does not interpret provisions or assess whether a specific proposal complies
• PlotDetect does not use generative AI to produce or modify planning data (see our AI Disclaimer)
• PlotDetect does not provide legal advice or replace the role of qualified town planners, heritage consultants, or legal professionals
• PlotDetect does not guarantee completeness — some provisions may involve subjective criteria, site-specific conditions, or recent amendments not yet reflected in the database

Coverage

PlotDetect currently covers select NSW local government areas, with expansion underway. Current coverage and data currency dates are available on request. Contact info@plotdetect.com.au for details.

Related Pages

• AI Disclaimer & FAQ — how deterministic data retrieval works, what AI is and is not used for, and answers to common questions from planning professionals and government stakeholders
• Audit Trail — query logging, data version history, retention periods, and NSW AIAF alignment