The city approved permits for Google to conduct demolition work on the exterior and atrium of the Thompson Center as part of the tech giant’s larger efforts to remake the building into its Chicago headquarters.

Google will remove the metal and glass skin on the 17-story building at 100 West Randolph St. and on its atrium, per information in permits issued Friday by the Chicago Department of Buildings and as first reported by the Chicago Sun-Times.

The estimated cost of the project is $6M, per the permit documents.

The demolition wasn’t completely unexpected, the Sun-Times reported. Previous renderings showed prospective views of the renovated edifice with new exterior and interior glazing that either discarded or muted the building’s current features.

The permit approval is an indication that the project may soon be underway.

Google announced plans in July 2022 to purchase the 1.2M SF Helmut Jahn-designed building for $105M after it undergoes renovations. The company said it anticipates it will move into the Thompson Center in 2026.

“The Thompson Center will provide employees with unparalleled public transit access as the only building in the city where six L train lines converge, easily connecting Chicago’s South, West and North sides,” Google said in a blog post at the time.