A ventilated facade system | rainscreen wall system is a cladding system with a plenum space or opening immediately behind which provides with aeration, drainage and thermal properties. It is usually an exterior cladding system mechanically attached and/or fused to a framework and secured to the building envelope; new or reconstructed. This external wall may be built either of masonry, concrete, or studwork and a layer of thermal insulation might be located either between studs or laid on the outer side of the substrate wall. The cladding elements are usually lag-bolted to the substrate wall by means of a framework being metal a preferred choice. The ventilation is produced by openings at the top and bottom of the cladding and by the open joint pattern created by the cladding. This ventilation allows for an exchange of cool or warm air between the exterior and the hollow space behind the panels, for venting moisture from the facade, increasing the current conditions inside the building due to the insulation between the building exterior material and the building envelope.