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

Sydney's property and planning agencies are sitting on thousands of duplicate digital images — photographs, scans and cadastral maps filed multiple times under different reference numbers — and the effort to clean up that backlog is moving slower than officials in comparable cities would tolerate. The problem spans everything from listings on the NSW Valuer General's database to construction documentation lodged with councils in Parramatta and Blacktown, where rapid Western Sydney development has accelerated the inflow of digital records since at least 2022.

The timing matters. The NSW Government is under acute pressure to cut planning approval times as the housing crisis dominates state politics, with Premier Chris Minns framing Labor's re-election prospects as a steep climb. Every bottleneck in the digital-records pipeline — including staff hours lost to manually identifying and removing duplicated imagery — adds friction to a system that already struggles with volume. Inner-city heritage assessments in Surry Hills and Newtown, for instance, routinely require photographic evidence matched against existing archival images, a process that grinds when the archive itself contains redundant files.

What Peer Cities Are Doing

The comparison with similarly sized global cities is not flattering. Singapore's Urban Redevelopment Authority completed a system-wide deduplication of its electronic submissions portal in late 2024, deploying perceptual hashing software that cut redundant image files by an estimated 34 percent across the national land registry. The City of London Corporation rolled out an automated flagging tool across its planning portal in March 2025, targeting duplicate heritage photographs submitted by surveyors — a problem the Corporation had publicly acknowledged cost roughly £200,000 a year in manual review hours. Toronto's City Planning division, which overhauled its Amanda permit system in 2023, built deduplication checks directly into the upload workflow, rejecting exact-match images at the point of submission.

Sydney has no equivalent automated gate at submission. The NSW Department of Planning's ePlanning portal, which handles development applications across the state's 128 local government areas, currently relies on individual councils to audit their own document stores. That decentralised model made practical sense when volume was lower. It is struggling now. The City of Sydney Council alone processed more than 4,800 development applications in the 2024–25 financial year, each of which can contain dozens of image attachments. Duplication creeps in when applicants resubmit amended plans without removing earlier versions, when scanning services batch-process physical documents and create near-identical files, and when heritage consultants recycle stock photography across multiple submissions in precincts like Chippendale and Ultimo.

Local Efforts and What Comes Next

Some councils are moving on their own. Parramatta City Council has been piloting an internal image-management protocol since January 2026, according to publicly available council meeting agendas, as part of a broader records-management review tied to its Parramatta Square precinct development program. The protocol requires staff to run a basic similarity check using open-source tools before archiving new submissions. It is a manual workaround, not an automated solution, but planners familiar with the process say it has reduced obvious duplication in the Parramatta CBD portfolio.

The State Archives and Records Authority of NSW, which sets retention standards for council documents, updated its Local Government General Authority disposal schedule in 2023 but did not address deduplication as a distinct data-quality issue. That gap is one reason the problem lacks a single owner across the sector.

For property buyers and developers, the practical consequence is straightforward: title searches and heritage reports that draw on council image archives can return conflicting or redundant visual records, requiring additional professional verification. Conveyancers working the Blacktown and Liverpool corridors — among the busiest transaction corridors in the country by volume — have raised the issue through the Australian Institute of Conveyancers NSW Division as a source of delays in settlement documentation.

The most immediate lever available is at the state level. If the ePlanning portal were updated to include a perceptual-hash check at upload — the approach Singapore and Toronto have already operationalised — the problem would shrink at its source rather than compound inside council archives. Whether the Department of Planning prioritises that fix alongside its broader digital-transformation agenda in the 2026–27 budget cycle is the question the sector is watching.