Berlin Tackles Duplicate Image Problem in City Records — and It's Ahead of London and Warsaw

Berlin's Senate Department for Urban Development confirmed this spring that its digital asset management systems contain an estimated 340,000 duplicate image files — photographs, architectural scans and planning maps stored twice, sometimes three times, across overlapping databases accumulated during two decades of piecemeal digitalisation. The redundancy is not just a storage headache. It is slowing down building permit reviews at processing centres in Mitte and Friedrichshain-Kreuzberg, and raising costs at a moment when the SPD-led coalition has staked significant political capital on cutting bureaucratic delays in housing approvals.

The timing matters. Berlin added roughly 16,000 new apartments to its housing stock in 2024, according to figures the Senate Department published in its annual construction report — far below the 20,000-unit annual target the coalition set in 2022. Every week shaved off a permit review cycle translates, in theory, into faster project starts. When planning officers in Pankow or Neukölln have to manually identify and delete duplicate site photographs before attaching the correct file to an application, that cycle does not get shorter.

How Berlin Compares With Other European Capitals

London's Greater London Authority began a systematic duplicate-image audit across its planning portal in January 2025, contracting a private data management firm under a framework agreement worth £2.1 million over three years. Warsaw's city digitalisation office launched a similar deduplication project in October 2024, targeting the ZDiZ — the city's road and infrastructure database — and reported clearing 180,000 redundant files within the first four months. Berlin, by contrast, has so far relied on an internal working group housed within the Senatsverwaltung für Stadtentwicklung, Bauen und Wohnen, without a separate procurement budget attached to the effort.

That in-house approach has its advocates inside the Senate administration. The working group draws on staff from the Geoportal Berlin project — the city's publicly accessible geographic information platform, which hosts more than 600 data layers and has been operational in its current form since 2019 — and from the Landesarchiv Berlin on Eichborndamm in Reinickendorf. Combining archival expertise with GIS technical knowledge gives Berlin a different skill mix than outsourced models. Whether it produces comparable results at the pace housing pressure demands is a question the Senate has not publicly answered.

Paris offers a cautionary parallel. The Direction de l'Urbanisme in the French capital ran a deduplication drive across its heritage photography archive in 2023 and found that automated hash-matching software — which identifies identical files regardless of filename — cleared about 60 percent of duplicates instantly, but the remaining 40 percent required human review because images had been slightly re-cropped or re-compressed when migrated between systems. Berlin planners working on the Geoportal project have acknowledged encountering the same problem, particularly with aerial photographs of the Tempelhof field and the Spree riverbank taken at different resolutions over successive years.

What the City Plans Next

The Senate working group is expected to present a formal methodology recommendation to the Stadtentwicklungsausschuss — the parliamentary committee overseeing urban development — before the summer recess ends in mid-August. Sources familiar with the committee's schedule, speaking generally about the agenda rather than about the contents of any submission, say the recommendation is likely to propose a hybrid model: automated deduplication software for straightforward duplicates, with a small trained review team handling edge cases. No procurement figure has been published.

For Berliners waiting on building permits — and for the architects and housing associations filing dozens of applications a month at district offices from Spandau to Lichtenberg — the practical upshot is modest but real. Cleaner image databases reduce the chance that a planning officer attaches the wrong site photograph to the wrong parcel reference, a category of administrative error that the Senate's own quality review flagged as a recurring problem in its 2023 internal audit. Getting rid of the duplicates will not solve the housing shortage. But it is the kind of unglamorous infrastructure fix that determines whether ambitious targets meet reality on the ground.