Level ceilings must be at least 7 feet high, and at least 6 feet 4 inches under beams, ducts and other obstructions. There is no height restriction under stairs. If a room has a sloped ceiling, at least one-half of the finished floor area must have a ceiling height of at least 7 feet. Otherwise, omit the entire room from the floor area calculations. If a room with a sloped ceiling meets the one-half-of-floor-area-over-7-feet requirement, then include allthe floor space with a ceiling height over 5 feet. Lofts and finished attics must be accessible by a conventional stairway or other access to be counted. If you can only reach the loft by climbing a ladder, it’s not part of the finished floor area regardless of the ceiling height.  Please heed these words--it may be the the attic finished to be a second bedroom will not be able to count as square footage at all depending on ceiling height and access!

According to the ANSI standards, finished areas which are not connected to the main residence by a finished hall or stairway must be listed separately. If you have to leave the house to get to the room, it’s not part of the finished floor area.