Brussels Discovers Thousands of Duplicate Photos in Digital Archives

Brussels' urban administration is sitting on a backlog it cannot easily quantify. Across the databases maintained by urban.brussels, the Brussels-Capital Region's planning and heritage directorate, thousands of image files have been catalogued multiple times under different reference numbers — the same facade photograph of a Rue de la Loi office block appearing in three separate dossiers, or an aerial shot of the Cinquantenaire park duplicated across both the heritage inventory and the environmental impact archive. The problem has a name inside city hall: duplicate image contamination.

This matters right now because the Region is mid-way through a structured digitisation programme. The move to consolidate physical planning records — many still held on paper or on obsolete CD-ROM archives at the Rue du Progrès administrative campus — was accelerated after the 2021 Brussels Regional Informatics Centre (BRIC) audit recommended that all departmental document stores be migrated onto a single interoperable platform by the end of 2027. That deadline is eighteen months away, and the duplicate problem is one of the reasons the migration is running behind schedule.

How the Duplication Built Up Over Thirty Years

The roots of the issue go back to the early 1990s, when individual Brussels communes began digitising their own planning archives independently. The nineteen communes that make up the Region — from Anderlecht to Woluwe-Saint-Pierre — each contracted separately with different scanning bureaux, often at different resolutions and with incompatible metadata schemas. When the Region created urban.brussels in 2017 by merging the former CRMS heritage body and the AATL urban planning department, it inherited two distinct image libraries that had never been reconciled against each other.

The problem deepened during the Covid-19 lockdowns of 2020 and 2021, when field inspectors working remotely submitted photographs through an emergency upload portal that had no deduplication filter. According to BRIC's 2021 audit report, roughly 34 percent of image assets ingested during that eighteen-month window were duplicates of files already held in at least one regional database. The portal was closed in September 2021 but the files it generated remained.

Molenbeek and Ixelles provide concrete examples of how localised the damage can be. The Molenbeek communal planning archive, which covers the dense residential grid around the Chaussée de Ninove corridor, contains building-permit photograph sets that were scanned first by the commune in 2004, again by the then-AATL in 2009 during a neighbourhood regeneration survey, and a third time during a 2019 Heritage Days documentation project run out of the Belvue Museum. Each scan was stored separately. None was cross-referenced.

The Technical and Legal Complications of Cleaning It Up

Deduplication is not simply a matter of deleting copies. Under the Belgian Archives Act, amended most recently in 2018, public bodies are required to retain original provenance records even when the content is identical to another file. That means urban.brussels cannot simply delete the redundant entries; it must instead create linking metadata that flags one file as the canonical record and the others as derivative instances. Writing those linkages for an estimated 200,000 flagged image files is labour-intensive work that the directorate's internal IT team, based at the Square de Meeûs offices, is not resourced to complete alone.

The Region awarded a framework contract to a Leuven-based document management firm in March 2026 to begin systematic deduplication work on the heritage inventory first, with the urban planning archive to follow. The contract runs until December 2027, aligned with the BRIC migration deadline. Officials have not published cost figures for the contract publicly.

For architects, heritage researchers, and neighbourhood associations who regularly submit Freedom of Information requests to urban.brussels, the practical advice for now is straightforward: when requesting image records for a specific address or zone, ask explicitly for a duplicate-status declaration alongside any file bundle. The directorate has confirmed it can flag known duplicates on request, even if the full deduplication project is unfinished. The Place Sainte-Catherine neighbourhood association used this approach successfully in a planning objection filed in April 2026, obtaining a clean, non-duplicated photograph record for a contested warehouse conversion on the Quai au Bois à Brûler.