Sixty square feet of storage space, in addition to closets, with a minimum height of six feet, which may be located in the basement. Said storage space shall have a fireproof ceiling with a minimum two-hour rating, a fire alarm system, an underwriter-approved method of automatic fire control and proper and adequate lighting. For age-restricted multifamily developments, a thirty-square-foot outdoor storage area shall be provided in lieu of a sixty-square-foot storage area.