The service core projects from the rear (northern side) of the tower with walls of painted concrete with off-form-patterned panels. The core fenestration is minimal, contrasting with the ample glazing of the adjacent northern elevation of the tower. The east and west elevations of the core have long, narrow ribbons of windows with high sills, and the north elevation has a column of small windows with a high sill and a spandrel panel of quartz aggregate. On the roof of the service core and the tower is a large, facebrick plant room and air-conditioning machinery.