Crucial to interstellar trade, conference centres house a large number of facilities to host business meetings, trade expos, product launches and any number of events related to business, commerce and trade. Typical conference centres would house meeting rooms of various sizes to accommodate small to large business meetings, as well as large halls for displaying products and conducting trade fairs. These large halls will have entrances that are large enough to enable even armoured vehicles and boats to be brought into the hall for display, which some are even large enough to accommodate light freighters. Conference centres will frequently have independent power supply or generators to provide power in case the city power supply is interrupted, enabling important trade events to continue even if surrounding areas are hit by a power outage. The cost of maintaining these buildings is quite significant, and the building owners will constantly vie with one another to host business conferences and trade expositions. When not in use for such purposes, smart building owners will allow events such as weddings and indoor sports events to be held, in order to maintain a steady stream of rental income.