At 220 meters tall, this proposed 50-storey apartment would be one of the tallest residential towers in Jakarta, and Indonesia. The tower would sit on a very small site, creating an extremely slender and elegant tower. But, it also made for a very challenging structure, with core slenderness ratio 1:24. As the architectural massing and spatial planning do not allow for outriggers, the core has to be buttressed by the perimeter columns, resulting in a very efficient dual system. Located in one of the most earthquake prone city, the perimeter column receives additional axial force approximately 50% of the total gravity load. It necessitates the use of steel composite columns and link beams, making it possibly the first of such structure in Indonesia.