Concrete is a fundamentally important material to offsite construction. Precast and pre-stressed units and formwork include elements such as the structural frame, supporting columns, panels, beams and flat slabs. These can be used to create most building types. The concrete elements may be factory-finished internally including services, windows, doors and finishes. Externally they can remain exposed in the final building. Precast concrete may be used with in-situ concrete or structural steel as part of a hybrid frame and can be integrated with cladding systems, volumetric and pod technology. Precast concrete systems are also used to rapidly build foundations. The concrete elements are usually to a bespoke design and cast in a factory environment, giving guaranteed quality for the finished product.