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

Sydney's built environment is drowning in duplicate imagery. Across the NSW Department of Planning's online portal, local councils from Blacktown to Bayside, and the sprawling digital asset libraries maintained by Infrastructure NSW, the same construction site photographs, heritage building scans and urban design renders appear repeatedly — filed under different names, stored in different systems, and costing public agencies real money in storage and retrieval time. The problem is more mundane than it sounds, and considerably more expensive.

The timing matters. With Metro West construction documentation ballooning — the project stretches across a corridor from the Sydney CBD to Westmead, with stations at places like Five Dock and The Bays — and the state government under pressure to accelerate housing approvals across Western Sydney, the volume of planning imagery being generated and catalogued has grown sharply. Digital asset management is no longer a back-office concern; it sits directly in the path of housing delivery.

What Sydney Is Actually Doing

The City of Sydney Council has, since late 2024, been running its digital asset library through a centralised platform that applies perceptual hashing — a technique that compares image fingerprints rather than raw file sizes — to flag near-identical files before they are archived. The council's library covers everything from photographs of Green Square Town Centre development stages to heritage imagery of the Rocks precinct. According to council budget documents, storage rationalisation formed part of a broader ICT efficiency program announced in the 2025–26 financial year.

Parramatta City Council's approach has been less systematic. Its planning portal, which handles development applications across one of the fastest-growing local government areas in the country, still relies largely on manual document review. Staff there have flagged internally that duplicate submissions — the same site photo attached to multiple DA documents — slow assessment times, though no formal audit figure has been published.

Property NSW, which manages the state's real estate portfolio including the Walsh Bay Arts Precinct and Barangaroo, has separately contracted with a Sydney-based digital asset firm to audit its image holdings. That contract, awarded in the second half of 2025, covers approximately 1.4 million files across the agency's systems, according to procurement records published on the NSW eTendering platform.

How Sydney Compares to London, Singapore and New York

London is further along. Transport for London completed a full deduplication audit of its project image archive in 2023, reducing its hosted storage volume by roughly 34 percent, according to the agency's published digital transformation report. The Greater London Authority has since mandated perceptual hashing as a minimum standard for any new infrastructure project documentation above £10 million.

Singapore's Urban Redevelopment Authority integrated AI-assisted image deduplication into its GovTech stack in 2022, as part of the Smart Nation programme. Every development application lodged through the Integrated Land Information Service is now screened at point of submission. The practical effect has been a measurable reduction in processing overhead, though Singapore's advantage is partly structural — it operates a single national planning authority rather than a patchwork of local councils.

New York City's Department of City Planning has struggled more, in ways that rhyme with Sydney's situation. Its ZoLa mapping platform — the Zoning and Land use Application — was expanded in 2024, but the agency's broader image archive remains fragmented across borough offices. A 2025 Government Accountability Office review of federal digitisation grants noted New York as a case study in the difficulty of consolidating legacy image stores across jurisdictions that were never designed to talk to each other.

Sydney sits somewhere in the middle of this spectrum. The City of Sydney's approach is comparatively sophisticated. Parramatta, Blacktown, and the outer growth corridors are not. That gap matters because most of the housing approval volume — the political priority the Minns government has staked its credibility on — runs through exactly those councils, not the inner city.

For residents or developers dealing with DA delays at councils in the Parramatta or Cumberland areas, the practical advice is simple: submit clean, uniquely labelled image files with each document package, avoid re-attaching photographs already included in earlier DA stages, and check whether the relevant council portal has published a digital submission guide. Several, including Liverpool City Council, updated their submission guidelines in early 2026. The backend systems may not be fixed yet. The front-end habits can be.