Advanced Prefabricated Construction is a technology that consists of assembling buildings or their components at a location other than the building site. The method controls construction costs by economizing on time, wages, and materials. Prefabricated units may include doors, stairs, window walls, wall panels, floor panels, roof trusses, room-sized components, and even entire buildings. There are two main families of prefab systems, 2D prefab and 3D prefab. These systems can be used on their own, used as hybrids with each other, or used in conjunction with traditional construction approaches. 2D prefab components are pre-cut, pre-sized, pre-moulded or pre-shaped elements that are assembled or installed on site. 2D Panels are non-volumetric systems that arrive on site ready for assembly. They might form the building envelope, stair cores, internal load bearing walls or lighter partitions. They might be open or closed panel systems, precast concrete panels or other panel types, all created through a range of advanced off-site manufacturing technologies. 3D prefab modular, sectional, volumetric or unitised systems are 3-dimensional structural units which are combined at site with other units or systems, or might comprise an entire small building. 3D systems include pods that are generally not structural modules, such as bathroom or kitchen pods.