Istanbul's Municipality Launches Crackdown on Duplicate Street Signage After Heritage Database Errors Surface

Istanbul's Metropolitan Municipality confirmed this week that an internal audit of its urban heritage image database had identified more than 340 duplicate or incorrectly tagged photographs used across planning documents, restoration permit files and public-facing tourism portals. The discovery, surfaced during a routine quality check by the municipality's Geographic Information Systems directorate, has put several pending construction reviews on hold and triggered an emergency replacement protocol across at least four district offices.

The timing matters. Istanbul is midway through an accelerated seismic-resilience programme that relies heavily on digitised building records — a programme that gained urgency after the February 2023 Kahramanmaraş earthquakes killed more than 50,000 people across southern Turkey. When photograph files attached to structural assessments turn out to be duplicates of unrelated buildings, or show facades that no longer exist, permit decisions can rest on evidence that belongs to a different address entirely. That is not a bureaucratic nuisance; it is a safety question.

The audit flagged problems concentrated in three areas of the city's archive: historical peninsula records covering Sultanahmet and Eminönü, the dense residential files for Kadıköy's inland streets near Moda Caddesi, and documentation tied to the ongoing Galata Tower precinct pedestrianisation project in Beyoğlu. In Kadıköy, district planning staff reportedly found the same exterior photograph of a 1930s apartment block on Mühürdar Caddesi attached to seven separate property files under different addresses. In the Galata precinct files, drone images from 2021 had been re-uploaded multiple times with conflicting GPS metadata, creating contradictory records about which facades had already been surveyed for reinforcement.

What Happened This Week

On Tuesday, the municipality's Department of Urban Transformation issued an internal circular — dated July 1, 2026 — instructing all district directorates to suspend approval of any restoration permit where the primary photographic evidence had not been independently cross-referenced against the Istanbul Cultural Heritage Inventory, maintained jointly with the Culture Ministry. The circular set a 21-day deadline for affected files to be re-documented with fresh site photography. Permits already issued before the audit began are not being revoked, but inspectors have been told to conduct physical site visits before any construction begins on flagged addresses.

The Istanbul branch of TMMOB, the Union of Chambers of Turkish Engineers and Architects, has been following the situation. The organisation, which has offices near Taksim Square and has previously raised concerns about the pace of earthquake-retrofitting approvals in the city, represents thousands of licensed professionals whose work depends on the accuracy of official documentation. Without reliable image records, engineers preparing structural reports for buildings in high-risk zones like Avcılar or Bağcılar cannot be confident their assessments match the actual physical state of the structures.

The scale of the problem is not entirely surprising. Istanbul's digital planning archive spans more than 1.4 million individual image files accumulated since a scanning programme began in 2009. The Metropolitan Municipality's own 2024 annual report acknowledged a backlog in metadata standardisation, though it did not quantify the extent of duplicate entries at that time. Replacing a contaminated image record requires not just uploading a new photograph but re-linking it to the correct land registry parcel number in the national TKGM database — a process that, according to the municipality's published workflow guidelines, takes between three and eight working days per file.

What Comes Next

The 21-day compliance window runs to July 22. District teams in Fatih, Beyoğlu and Kadıköy — the three districts with the highest concentration of flagged files — have been given priority access to a pool of municipal photographers and licensed surveyors contracted under the municipality's ongoing Kentsel Dönüşüm (Urban Transformation) framework. Property owners with active permit applications in those districts are being contacted individually by their local planning office and advised to check whether their file is among those requiring re-documentation.

Architects and engineers submitting new applications in the meantime are being asked to attach a standardised cover sheet confirming that every photograph included was taken specifically for that file, with GPS coordinates embedded. It is an extra step, and it will slow some submissions. But with earthquake-proofing decisions depending on visual evidence, the municipality appears to have concluded that slower is safer than wrong.