St Petersburg heritage authority denies terrace plan for Karl Miller mansion

St Petersburg's heritage authority said no terrace was planned for the Karl Miller mansion on St Isaac's Square. It said circulating images showed an unapproved design sketch.

The Committee for State Control, Use and Protection of Historical and Cultural Monuments told 78.ru that the project had undergone repeated revisions. The authority said the version approved in 2025 preserved the building's historic appearance and had received expert endorsement.

Heritage campaigners had raised concerns about images showing a terrace with panoramic glazing above the main facades. The committee said the roof ridge heights formed part of the monument's protected features.

The mansion was damaged in an October 1 fire affecting approximately 2,000 square metres of the building and a further 250 square metres of a neighbouring roof. The fire was fully extinguished a day later.

The Investigative Committee identified a possible breach during welding work as the preliminary cause. A criminal case was opened over alleged violations of safety rules during construction or other work.

The building developed from eighteenth-century structures. It was substantially rebuilt in 1879–1880 for engineer Karl Miller to a design by his brother Ferdinand. It received regional cultural heritage status in 2021.

St Petersburg Governor Alexander Beglov previously said restoration should be completed by the end of 2028.