Perth's Duplicate Image Problem: How the City Stacks Up Against Singapore, Amsterdam and Toronto

Perth's planning and property sector is grappling with a surge of duplicate and conflicting imagery embedded in development applications, heritage registers and infrastructure databases — and the City of Perth, along with the Western Australian Planning Commission, is still catching up to cities that moved on the problem years ago.

The issue matters now because of scale. The Metronet rail expansion, AUKUS-related construction activity around HMAS Stirling on Garden Island, and a housing approval backlog driven by record immigration to WA have pushed the volume of digital planning documents to levels the state's data systems were not originally designed to handle. When duplicate site photographs, aerial images or engineering renders sit unchecked inside approvals workflows, assessors can spend hours reconciling files that should have been auto-flagged — slowing decisions on projects worth tens of millions of dollars.

What Perth Is Doing

The City of Perth's digital transformation program, centred on its Hatch online development portal launched in 2022, introduced some automated file-checking at the point of submission. But property consultants working on projects in Northbridge and the East Perth Redevelopment Authority precinct have observed that the deduplication logic built into Hatch applies only to documents lodged after that launch date. Older records migrated from legacy systems — some dating to the 1990s — still carry redundant imagery that can reappear in heritage assessments or environmental overlays.

The Western Australian Planning Commission has been progressively digitising its statewide mapping datasets under the OneMap WA project, a collaboration with Landgate headquartered in Midland. OneMap has significantly improved geospatial data consistency since its phased rollout from 2020, but deduplication of raster imagery — the actual photographs and rendered site images attached to individual applications — has lagged behind the vector mapping work.

Landgate, the state's land information authority, publishes a publicly accessible data quality dashboard. As of its most recent quarterly update, imagery datasets for the Perth metropolitan area carried a documented duplication rate that Landgate described as requiring ongoing remediation — though the authority has not published a specific percentage figure for the current financial year. The City of Swan and the Town of Victoria Park have separately flagged the issue in their annual IT governance reports, citing delays in processing development applications in high-growth corridors along Tonkin Highway and Albany Highway respectively.

How Singapore, Amsterdam and Toronto Handle It

Singapore's Urban Redevelopment Authority runs a centralised image ingestion pipeline called CORENET X, which went fully live in 2024. Every file submitted for a building plan approval passes through a hash-matching algorithm that flags duplicates before a human assessor ever opens the document. The authority has publicly stated the system cut document-related assessment queries by a material margin in its first year, though specific figures have not been independently audited.

Amsterdam's municipality uses a federated model. The city's Omgevingsloket platform, part of the Dutch national environment permitting framework active since January 2024, pushes deduplication responsibility back to the submitting party through machine-readable file standards — applicants whose packages contain flagged duplicates receive an automated rejection within minutes. Toronto, by contrast, relies on its Automated Land and Property System, which embeds image fingerprinting at the point of document upload through a partnership with the municipal IT division and an external vendor contracted in 2023.

Perth's position sits somewhere between Amsterdam and Toronto: there is automation, but it is partial, and its coverage of historical records is incomplete. The gap is not unique to WA — Brisbane and Adelaide face comparable legacy-data challenges — but Perth's rapid population growth, currently running at one of the fastest rates of any Australian capital, means the volume pressure is higher than most.

For developers and their consultants submitting applications through Hatch or directly to the WAPC, the practical advice is straightforward: run your own deduplication check before lodgement. Free tools including Google's duplicate image finder and open-source scripts built on the Python imagehash library can process a folder of site photos in under two minutes. The City of Perth's development services team on Hay Street can also be contacted before formal lodgement to flag potential file conflicts — a step that costs nothing and can shave days off an assessment timeline at a time when every week matters on a construction calendar.