This rental office building, with retail stores on the first floor and offices in the second to seventh floors is located in the center of Sendai City. The aim was to reduce the load on the environment while forming a comfortable office environment in this cold region. The use of flat slabs and flat beams in this base-isolated frame structure has created an opened-up inside space, and with just a suitable amount of earthquake-resistant exterior walls, the heat loss during winter is kept to a minimum. The sculptured exterior with outside pilasters cut the amount of direct sunshine on the building, and inside there are no column shapes around the window areas. The openings have been designed so they can be opened and closed, allowing for natural ventilation.