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…