How London's Planning System Let Duplicate Images Flood Property Records — and Why It Now Has to Clean Up the Mess

The Land Registry's digital estate in London contains tens of thousands of duplicate property images — scanned documents, aerial photographs and site plans filed multiple times across overlapping council systems — and untangling them has become an unexpected obstacle to the Starmer government's push to accelerate planning decisions across the capital. The problem is not new, but it has acquired fresh urgency as Whitehall leans harder on local authorities to cut decision times and unlock housebuilding targets.

The immediate pressure point is the government's Planning and Infrastructure Bill, introduced in the spring of 2026, which requires local planning authorities to integrate their case management systems with a national digital land data platform by the end of 2027. For dozens of London boroughs still running on legacy document management software, that deadline exposes a years-long failure to maintain clean image records — a failure that now has to be resolved at speed and, in many cases, at considerable cost to already stretched council budgets.

How the Duplication Built Up Over Three Decades

The roots of the problem stretch back to the early 1990s, when individual London boroughs began scanning paper planning files independently, with no common file-naming convention, no shared metadata standard and no mechanism to flag when the same site plan or architectural drawing appeared in multiple applications. Southwark Council, for example, processed thousands of applications along the Old Kent Road corridor during successive regeneration rounds; the same baseline site imagery was frequently re-submitted by applicants and logged as a fresh document each time.

The Greater London Authority, which took over strategic planning functions after its creation in 2000, added another layer. The GLA's own mapping and visualisation unit — based at City Hall, now at the Crystal building in Royal Docks — generated its own archive of aerial and ground-level imagery tied to Opportunity Area frameworks. Where those frameworks overlapped with borough-level applications, duplication compounded. The London Legacy Development Corporation, which has overseen the Queen Elizabeth Olympic Park area in Stratford since 2012, estimates it holds several thousand image records that cross-reference identically with Tower Hamlets and Newham borough files, according to public documentation accompanying its 2025-26 annual report.

His Majesty's Land Registry flagged the scale of the problem in a 2023 review of its Local Land Charges migration programme, which transferred responsibility for local land charge registers from individual councils to a centralised national register. That transfer, which London boroughs largely completed between 2020 and 2024, required matching images to unique property identifiers for the first time. The matching exercise revealed a duplication rate in some inner-London boroughs running above 30 percent of scanned document records — figures that surprised even some of the officials managing the migration.

What Reform Looks Like in Practice

The practical fix is neither glamorous nor cheap. Councils must run deduplication software across their archives, manually verify ambiguous matches and retire redundant files to a read-only archive rather than delete them outright — deletion would breach document retention obligations under the Local Government Act 1972. Lambeth Council began a formal deduplication project in January 2026, contracting a specialist records management firm to process an estimated 1.2 million scanned images held in its Uniform planning system. Islington Council has taken a different approach, embedding deduplication into its ongoing migration to a new cloud-based planning platform, with completion targeted for March 2027.

The costs are not trivial for authorities already facing significant budget pressure. Sector estimates, drawn from procurement frameworks published on the Crown Commercial Service portal, put per-borough deduplication contracts in the range of £150,000 to £400,000 depending on archive size and system complexity. For boroughs in the middle of wider digital transformation programmes — Hackney, which suffered a serious cyber attack in 2020 and has been rebuilding its IT infrastructure since, is one example — the deduplication work has had to queue behind more urgent system recovery.

The GLA is now funding a pan-London working group, convened through the Planning Officers Society, to develop a shared technical specification that boroughs can apply consistently before the 2027 integration deadline. Whether that working group can produce guidance quickly enough to be useful to boroughs already mid-project is the central practical question heading into the second half of 2026. Boroughs that miss the national platform deadline face the prospect of having planning applications processed through a manual workaround that planning reform advocates say would negate much of the efficiency gain the whole programme is meant to deliver.