Complex sentence: Attached on the south side of the building is a four-story, concrete-framed, glass and aluminum addition, which houses a parking garage's entrance and exit, meeting spaces, hotel service facilities, a kitchen, and a room for mechanical equipment.
Split into simpler sentences: Attached on the south side of the building is a four-story, concrete framed, glass and aluminum addition. The addition houses a parking garage's entrance and exit, meeting spaces, hotel service facilities, a kitchen, and a room for mechanical equipment.