Duplicate Images Are Swamping Sydney's Planning Portal — Here's How the City Stacks Up Against London and Toronto

Sydney's planning and property agencies are dealing with a quiet but costly problem: thousands of duplicate images clogging digital submission portals, slowing approval times and inflating storage costs at a moment when the NSW government is trying to fast-track housing approvals across Western Sydney and the inner ring.

The issue — duplicate image replacement, or the systematic identification and purging of identical or near-identical files uploaded by applicants, agents and government staff — has emerged as a genuine administrative drag inside the NSW Planning Portal, the centralised online system through which development applications, building certificates and related documents are lodged across the state's 128 local government areas.

The timing matters. The Minns government has staked much of its housing policy credibility on the planning system's speed and transparency. Any bottleneck that delays a DA in Parramatta or a housing approval in Campbelltown feeds directly into a political argument the Premier acknowledged this week he needs to win convincingly.

What Sydney Is Actually Doing

The NSW Department of Planning, Housing and Infrastructure has been piloting automated deduplication tools within the portal infrastructure managed from its Parramatta Square headquarters. The approach uses perceptual hashing — software that generates a fingerprint for each image file and flags copies before they are formally ingested into the document management system. Property NSW, which manages a large tranche of government real estate data, has run a parallel internal review of its asset imagery since late 2025.

On the ground in suburbs like Blacktown and Liverpool, council planning officers say the volume of duplicate files attached to multi-lot subdivision applications has been a known friction point for years. A standard subdivision DA for a 20-lot site in the Austral-Leppington Precinct, for example, can arrive with several hundred attached images, a significant proportion of which are identical site photographs submitted at different stages by the same surveyor or architect.

Sydney's approach contrasts with what London and Toronto have built. Transport for London's asset management division implemented deduplication protocols across its engineering image library in 2023, integrating the process into its existing BIM — Building Information Modelling — workflows so duplicates are rejected at upload rather than caught downstream. Toronto's City Planning division, which handles roughly 5,500 development applications per year according to the city's own published data, embedded deduplication directly into its Amanda permitting platform, cutting redundant storage by an estimated 30 percent in the first year of operation. Sydney has no publicly confirmed equivalent figure yet.

The Global Gap — and Where Sydney Can Close It

The core difference is where in the workflow the problem is addressed. London and Toronto built rejection logic at the front door. Sydney is still largely cleaning up after the fact, which means staff time is spent on remediation rather than prevented from being spent at all.

Singapore's Urban Redevelopment Authority, which manages one of the world's most digitised planning systems, went further still — its Corenet X platform, upgraded in 2024, uses AI-assisted content comparison to flag not just identical files but visually similar images that may represent slight re-crops or re-exports of the same original photograph. That capability does not yet exist inside the NSW Planning Portal at a system-wide level.

The practical stakes are not abstract. Cloud storage costs for government document management systems are billed by volume. A 2024 NSW Audit Office report on digital government infrastructure noted that data storage expenditure across NSW agencies had grown substantially over the preceding four years, though the specific contribution of duplicate files was not isolated in that document.

For planning applicants in suburbs like Penrith or Rouse Hill who submit large DAs, the immediate advice from planning consultants is straightforward: audit your own image folders before uploading, use consistent file naming conventions, and where possible consolidate site photographs into a single clearly labelled PDF rather than attaching dozens of individual JPEGs. That won't fix the system, but it reduces the chance that a duplicate image triggers a manual review request and adds weeks to an approval timeline.

The NSW Department of Planning, Housing and Infrastructure has indicated it intends to publish an updated digital submission guide for applicants later in 2026. Whether that guidance includes explicit deduplication requirements — as Toronto's submission standards now do — will signal how seriously the state is treating a problem that its peer cities largely solved two years ago.