Located along Metro’s new Silver Line, the Reston Station Building 4 project is a mixed-use, transit oriented 20-story building with 450 residential units and 720 parking spaces built over a new WMATA transit garage. The project includes plaza level retail spaces, an outdoor amenity plaza and clubhouse on the 10th floor, amenity spaces on the roof, and a roof-top swimming pool. The superstructure employs a combination of post-tensioned con­crete flat plates and conventionally reinforced concrete flat slabs, and a large transfer structure at the bottom of the residential parking levels to accommodate bus access to the Metro areas below.