Data Sources

Every score on Address Twin is calculated from official government open data. Below is a complete inventory of every dataset we use, the agency that publishes it, the licence terms, update frequency, and known caveats. No proprietary models, no black-box estimates.

Property Sales Transactions

Landgate (Western Australian Land Information Authority)

Source

Settled property sale records — contract date, settlement date, sale price, property type, land area, and floor area for houses, units, townhouses and vacant land.

Licence: Creative Commons Attribution 4.0
Update Frequency: Monthly
Coverage: All WA property transactions

Caveat: Bulk historical data is open under CC-BY. Real-time/recent transaction feeds and individual property attributes may require a commercial licence.

Bushfire Prone Area Mapping

Department of Fire and Emergency Services (DFES) WA

Source

Designated bushfire prone areas in WA showing risk classifications used for building permits, BAL (Bushfire Attack Level) assessment, and planning.

Licence: Creative Commons Attribution 4.0
Update Frequency: Annual (or after major review)
Coverage: Entire state of WA

Caveat: Risk classifications change over time. Official BAL assessments must be performed by qualified practitioners.

Crime Statistics

Western Australia Police Force

Source

Recorded offences by police district and suburb. Categories include theft, burglary, property damage, assault, drug offences and others.

Licence: Open data (publicly published)
Update Frequency: Quarterly
Coverage: All WA suburbs

Caveat: Reported offences only — undetected/unreported crime is not captured. Rate-per-1000 figures depend on Census population estimates.

Air Quality Monitoring

Department of Water and Environmental Regulation (DWER) / EPA WA

Source

Real-time and historical air quality readings from EPA monitoring stations — PM2.5, PM10, NO2, O3, SO2, CO with AQI calculations.

Licence: Open access (free API registration)
Update Frequency: Hourly (live monitoring)
Coverage: Perth metropolitan stations and select regional sites

Caveat: Monitoring coverage is sparse outside Perth metro. Outer suburbs use the nearest station — actual local air quality may differ.

Contaminated Sites Register

Department of Water and Environmental Regulation (DWER) WA

Source

EPA-listed contaminated sites in WA with classification status, contaminants of concern, and remediation status.

Licence: Open data (publicly searchable register)
Update Frequency: Monthly (as sites are classified)
Coverage: All sites formally investigated and classified

Caveat: The register is not exhaustive — sites may be contaminated but not yet investigated, classified or recorded.

Public Transit (GTFS)

Transperth / Public Transport Authority WA

Source

Train stations, bus stops, ferry terminals, routes and timetables in standard GTFS format.

Licence: Open data
Update Frequency: Monthly (GTFS schedule updates)
Coverage: Perth metropolitan public transport network

Caveat: Stop proximity does not capture service frequency or reliability. Real-time disruptions are not in the static GTFS feed.

School Profiles & ICSEA

Australian Curriculum, Assessment and Reporting Authority (ACARA)

Source

School name, type, sector, enrolment count, and ICSEA (Index of Community Socio-Educational Advantage) rating.

Licence: Conditional use (My School download)
Update Frequency: Annual
Coverage: All Australian schools

Caveat: ICSEA is a proxy for student background, not a direct measure of school quality. NAPLAN results are separate and require additional access.

Census Demographics

Australian Bureau of Statistics (ABS)

Source

Population, age distribution, household income, tenure (owner/renter), median rent, median mortgage, ancestry, employment.

Licence: Creative Commons Attribution 4.0
Update Frequency: Quinquennial (every 5 years — next: 2026)
Coverage: All Australian SA1/SA2/SA3 statistical areas

Caveat: 2021 data is current as of August 2021. Fast-growing suburbs may show outdated population/demographic figures.

SEIFA Socio-Economic Index

Australian Bureau of Statistics (ABS)

Source

IRSAD (Index of Relative Socio-economic Advantage and Disadvantage) decile per SA2. 1 = most disadvantaged, 10 = most advantaged.

Licence: Creative Commons Attribution 4.0
Update Frequency: Quinquennial (with Census)
Coverage: All Australian SA2s

Caveat: Composite index — a high SEIFA decile does not mean an absence of disadvantaged households.

Geocoded National Address File (GNAF)

PSMA Australia / Geoscape Australia

Source

Authoritative geocoded address dataset for Australia — every official address with latitude/longitude, used as the address spine for the platform.

Licence: Creative Commons Attribution 4.0
Update Frequency: Quarterly
Coverage: All Australian addresses (~14 million)

Caveat: GNAF reflects registered addresses — new subdivisions or recently changed addresses may lag by up to a quarter.

Mapbox Mapping

Mapbox

Source

Base map tiles, geocoding for the search bar, and interactive map rendering.

Licence: Commercial — used for base map tiles
Update Frequency: Continuous
Coverage: Global, with detailed Australian coverage

Caveat: Mapbox is a commercial service. The free tier covers initial usage; high traffic may require a paid plan.

Attribution

Address Twin acknowledges the use of open data published by the agencies above. Data is used under the terms of each respective licence (linked above). This platform makes no claim of ownership over the underlying datasets — we provide an aggregation, scoring and visualisation layer on top.

See the scoring methodology for how each dataset contributes to the suburb score, and the legal disclaimers for the limitations of using this data for property decisions.