London Leads Push to Purge Duplicate Property Images From Planning Records — But Other Cities Are Moving Faster

Thousands of planning applications lodged with London boroughs contain duplicate, mislabelled or recycled photographic evidence — a bureaucratic problem that, according to digital records specialists working with local authorities, is quietly slowing down housing approvals at a moment when the Starmer government has staked much of its domestic agenda on accelerating exactly that process. The issue is not new, but pressure to fix it is intensifying.

The problem matters now because the Planning and Infrastructure Bill, currently before Parliament, places new obligations on local planning authorities to maintain searchable, digitised records of applications. Duplicated images don't merely clutter databases — they create legal ambiguity about which photographic evidence was relied upon when a decision was made. In a judicial review, that ambiguity can be costly. Hackney Council and Tower Hamlets Council, both managing substantial development pipelines along the Lea Valley corridor and around Whitechapel respectively, have each begun internal audits of their application archives, though neither has published findings to date.

What the Duplication Problem Actually Looks Like

A planning application for a mid-terrace conversion in Stoke Newington, for instance, might contain sixteen photographs where four are genuinely distinct views of the property — the rest being near-identical shots uploaded repeatedly, sometimes under different file names, by agents who bill by the submission rather than the image. Officers reviewing the file must manually identify which images are material. At scale, across hundreds of applications a month, this consumes significant officer time. The Greater London Authority's Planning Datahub project, launched in partnership with the Open Digital Planning programme in 2023, has been attempting to standardise how images are tagged and stored across all 33 London boroughs, but the rollout has been uneven.

Southwark Council joined the Open Digital Planning pilot in early 2025, and staff there began using automated deduplication tools — software that flags photographs sharing more than 85 percent of their pixel data — to pre-screen incoming submissions. The approach, while not yet borough-wide, reduced manual image review time in a trial cohort of applications by a measurable margin, according to the programme's own published progress notes from December 2025.

Amsterdam and Toronto Are Running Ahead

London's record looks patchier against what other major cities have done. Amsterdam's Gemeentelijk archief — the city's municipal archive — completed a full deduplication sweep of its digital planning image database in 2024, working with the Netherlands' national Digitaal Erfgoed programme. Every photograph attached to a planning record since 2018 was processed through hash-matching software, and duplicates were flagged and quarantined rather than deleted, preserving the legal chain of evidence. The city reported the exercise covering roughly 2.3 million images.

Toronto, managing its own housing-supply crisis under Ontario's provincial planning reforms, embedded image deduplication requirements directly into its ePlans portal in January 2025. Applicants submitting duplicate files now receive an automated rejection notice before the application is formally lodged, pushing the problem back to agents rather than to officers. The City of Toronto's Planning Division confirmed the change in its 2025 Annual Report on Development Activity, noting a drop in average file sizes for residential applications in the first two quarters of the year.

London has no equivalent mandatory gate yet. The Open Digital Planning programme is voluntary for boroughs, and the Planning and Infrastructure Bill, for all its ambitions, does not currently specify image-deduplication standards as a requirement. Camden Council and Islington Council have both indicated interest in joining the Open Digital Planning cohort, but as of July 2026 neither has formally signed on.

For developers and their agents, the practical advice from planning consultants active in the capital is straightforward: audit your own submissions before lodging. Remove any photograph that appears more than once, ensure each image file carries a unique, descriptive name, and check that the images referenced in the design-and-access statement match the images in the application package. Boroughs are increasingly noting submission quality in their pre-application feedback, and at least two — Lambeth and Greenwich — have begun flagging image irregularities as a ground for requesting further information, which pauses the statutory determination clock. In a market where every week of delay carries a financing cost, that is a pressure agents are starting to take seriously.