Sydney's Digital Property Records Plagued by Thousands of Duplicate Images

Sydney's property and planning agencies are sitting on tens of thousands of duplicate digital images embedded across development application databases, council archives and state government land registries — and the systems designed to catch them are years behind those operating in comparable global cities. The problem is not cosmetic. Duplicate images in planning records slow assessments, inflate storage costs and, in some cases, have been linked to errors in heritage listings and land valuations.

The issue has sharpened in 2026 because NSW is processing a record volume of development applications, driven by the state government's housing targets under the Transport Oriented Development program, which rezones land within 400 metres of certain train stations. The NSW Department of Planning, Housing and Infrastructure is handling applications across more than a dozen Sydney council areas simultaneously, and the duplication problem compounds with every batch upload from developers and certifiers who submit the same site photographs multiple times across different portal submissions.

What Sydney Is — and Isn't — Doing

The NSW Spatial Digital Twin, managed through the Department of Customer Service and running out of the Pyrmont-based Deerpark data precinct, has been touted as the state's answer to digital asset management at scale. The platform uses metadata tagging and geospatial indexing to flag redundant image files across linked datasets. But the system currently covers land parcels under the SEED (Sharing and Enabling Environmental Data) portal, not the full suite of council DA systems, meaning large tranches of records from councils like Cumberland, Liverpool and Parramatta City still run their own image libraries with no automated deduplication layer.

Parramatta City Council, which processed more than 4,200 development applications in the 2024–25 financial year according to its annual report, relies on its Pathway software system — a platform used by dozens of councils across Australia — which has known limitations around image deduplication at the attachment level. Council staff manually review flagged files in many cases. That is a significant lag compared to what cities like Amsterdam and Toronto have already deployed.

Amsterdam's Digitaal Stelsel Omgevingswet, the national framework for environmental permit data that the Netherlands rolled out progressively from 2022, uses AI-assisted hash comparison to eliminate duplicate images at the point of upload, before a file enters the system. The City of Toronto, meanwhile, integrated perceptual hashing into its Amanda 7 permitting platform in 2023, reducing image storage redundancy in planning records by a reported 34 percent within the first 12 months, according to a presentation delivered at the 2024 International Association for Public Participation conference in Vancouver.

The Cost and the Competition

Cloud storage is not free. NSW government agencies collectively spend tens of millions of dollars annually on digital storage contracts, and while the exact figure allocated to planning-related image data is not publicly broken down in budget papers, the inefficiency is measurable. A 2025 audit by the NSW Audit Office of digital asset management practices across six agencies found that data redundancy — including duplicate files of all types — contributed to storage cost overruns in four of the six agencies reviewed. The audit did not name individual departments in its findings.

London's Planning London Datahub, operated through the Greater London Authority and headquartered in City Hall at Kamal Chunchie Way in Newham, has gone further still, mandating that any image submitted to a borough planning portal passes through a centralised deduplication API before entering the record. The GLA began enforcing this requirement for all 32 London boroughs from January 2025.

Sydney has the infrastructure ambitions but not yet the mandated standards. The NSW government's Digital Restart Fund, administered through Service NSW, has allocated grants to council digital transformation projects, and several Western Sydney councils have applied for funding in the current round. Whether those grants will be directed toward deduplication tooling specifically depends on individual council ICT priorities.

For developers, certifiers and anyone submitting documents through the NSW Planning Portal on Macquarie Street, the practical advice is straightforward: compress and rename image files with unique identifiers before upload, avoid batch-submitting the same photograph across multiple attachments, and check the portal's file management guide, updated in March 2026, which now explicitly flags deduplication as a submission best practice. It will not fix the systemic gap, but it will stop making it worse.