Several rooms can be precast at one time with a new three-dimensional precasting system used by a Korean corporation. The Daewoo Building System (DWS) replaces conventional precast concrete panel construction with mass-produced three-dimensional precast concrete modules. DWS is used to erect complete buildings with mass-produced concrete modules, facilitating faster finishing. The easier construction also reduces the amount of manpower needed. The system was first applied for high-rises in Korea in the construction of employee apartments at the Changwon light vehicle production plant.