An air-conditioned multipurpose facility generally used for meetings, conventions, and the display of merchandise by a wide variety of industrial groups, professional groups, and trade organizations. The size of the facility ranges from small to very large sometimes over more than 2 million square feet (approximately 18 hectares). The interior must be flexible so that it can be divided into varioussized spaces. Regardless of size, a convention center requires meeting spaces, movable partitions to subdivide these spaces, sanitary facilities, loading docks, adequate heating, cooling, electrical and communications equipment, and trained maintenance staff.