The following buildings and facilities are not covered by this Code: Residential buildings consisting of less than four dwelling units; Structures, sites, and equipment directly associated with the actual processes of construction, such as scaffolding, bridging, materials hoists, or construction trailers; Observation galleries less than 150 square feet and used primarily for security purposes; Nonoccupiable spaces accessed only by ladders, catwalks, crawl spaces, very narrow passageways, or nonpassenger freight elevators and frequented only by service personnel for repair purposes including, but not limited to, elevator pits, elevator penthouses, and piping or equipment catwalks; Transportation vehicles; Existing buildings or facilities not undergoing any addition, alteration, or change in use as defined in Regulation .05 of this chapter; and Existing buildings and facilities undergoing alteration for the sole purpose of complying with the Americans with Disabilities Act, which requires removal of architectural barriers in existing buildings and facilities where removal is readily achievable. This Code applies to all new construction, additions, alterations, and changes of use of certain buildings and facilities in Maryland, as follows: Covered multifamily dwellings as defined in Regulation .05 of this chapter; State and local government buildings and facilities, including transit facilities; All other buildings and facilities, including buildings and facilities used or owned by private clubs and religious organizations, except those listed in §A of this regulation.