Religious buildings are structures with large open interiors which are built for religious worship, prayer, or ceremonies. They often have prominent towers, spires, and domes rising above or beside the main structure. Detached baptistries, campaniles, minarets, and parish houses are counted as separate structures.

Religious buildings may be nearly identical in appearance to other types of buildings, such as halls, or capitol buildings. In this case, it is their original purpose as houses of worship that determines the building type.

If a house of worship occupies a building that is indistinguishable from an ordinary multi-story building type (low-rise, house, etc.) then the structure is listed as a multi-story building with church, synagogue, etc. as its usage. Houses of worship (other than pagodas) which are divided into multiple regular floors are classified as regular buildings.