Completed in 2012, the residential building on the Außenalster, which was created from the demolition and restructuring of an old administrative building, comprises two nested 3½-storey buildings with 12 exclusive condominiums and an access building. The mullion-and-transom façade of natural stone and sheet metal panels has balconies and terraces with glass railings all around. Interior differential staircases were cleverly transferred to the balconies. Sound insulation, thermal insulation and solar protection are guaranteed by the triple insulating and double solar control glazing of the windows.