How London's Planning System Ended Up Buried in Duplicate Images — and What's Being Done About It

London's planning archive has a problem that predates the current Labour government, predates Sadiq Khan's mayoralty, and predates the digital transformation of council systems: tens of thousands of duplicate images cluttering application files, slowing case officers, and making public access to planning records far harder than it should be.

The issue matters now because the Starmer government has placed planning reform at the centre of its domestic agenda. The Planning and Infrastructure Bill, currently working through Parliament, places new obligations on local authorities to digitise and standardise their records. That means councils across the capital face a hard deadline to clean up legacy systems before the new framework kicks in — and the scale of the duplication problem is only now becoming clear to many of them.

A Paper Trail That Never Quite Went Digital

The roots of the problem go back to the early 2000s, when councils began scanning physical planning files into digital systems. Tower Hamlets, Southwark, and Islington were among the first London boroughs to roll out electronic document management platforms, but the migration was inconsistent. Files scanned multiple times, re-uploaded during system migrations, or submitted in duplicate by applicants and their agents piled up without any automated deduplication. By the time cloud-based portals replaced the first generation of systems — a wave that hit most London boroughs between 2014 and 2019 — the legacy clutter had already been imported wholesale.

The Greater London Authority's Planning London Datahub, launched in 2021 to aggregate planning data across all 33 London boroughs, exposed the scale of the issue. Analysts working with the platform identified that a significant proportion of uploaded documents across multiple boroughs were exact or near-exact duplicates, in some cases the same site photograph appearing dozens of times within a single application file. Camden's local plan evidence base, for example, drew on document repositories that staff had flagged internally as containing redundant files stretching back to applications submitted as far back as 2007.

The problem is not merely aesthetic. Case officers at busy London boroughs — where application volumes run into the thousands annually — must navigate these bloated files when preparing committee reports. Developers and their agents, many of them operating out of offices in Fitzrovia and around the South Bank, have complained through professional bodies that searching public registers for comparable decisions is made unnecessarily difficult by the noise in the system.

Reform Pressure and the Path Forward

The Planning and Infrastructure Bill sets a deadline of April 2028 for all English local planning authorities to comply with new data standards published by the Department for Housing, Communities and Local Government. Those standards include requirements for unique document identifiers — a technical fix that, if applied retroactively, would make duplicate detection straightforward. Several London boroughs, including Hackney and Lewisham, have already begun pilot programmes to audit their existing document libraries ahead of the deadline.

The Open Planning project, run by the charity mySociety and part-funded through the GLA's Digital Infrastructure programme, has been developing open-source tools designed specifically to help councils identify and remove duplicate records. The project held a working session with planning officers from six boroughs at City Hall on 17 June 2026, the first formal convening of its kind, according to the programme's published event calendar.

For the public, the practical consequence of inaction is a planning register that remains frustrating to use. Anyone trying to track a major development — say, along the Silvertown Tunnel corridor in Newham, or around the Old Kent Road regeneration zone in Southwark — faces document indexes that can run to several hundred entries, many of them redundant.

Boroughs that want to stay ahead of the April 2028 compliance deadline should begin document audits now rather than wait for central guidance. The tools exist; the political pressure from Westminster is real; and the window for a managed clean-up, rather than a last-minute scramble, is narrowing fast.