Jasper is a 430-foot (130m) residential skyscraper located at 45 Lansing Street in the Rincon Hill neighborhood of San Francisco, California. The tower contains 320 residential units on 39 floors and 4 levels of subterranean parking. The tower is constructed with post-tensioned slab, concrete shear wall core and founded on a 7-foot mat foundation. Typically for a residential project, concrete is selected for its noise reduction and fireproofing attributes. A post-tensioned concrete slab was used to minimize the floor-to-floor height so that more stories could be placed with the building height envelope. Due to the small core dimension of 31’x32′, and core height-to-width ratio of 12.9 to 1 (400′ to 31′), stiffness of concrete core is required to meet building drift criteria. The lateral system is a concrete core shear wall with concrete moment frames. The building lateral design utilized the Tall Building Guidelines and performed a peer review process by a third party as required by the city of San Francisco.