Twenty-two buildings are in NYU's undergraduate housing system in the United States. In general, NYU residence halls receive favorable ratings, and some are opulent. Many rooms are spacious and contain amenities considered rare for individual college residence hall rooms, such as kitchens and living rooms/common areas, one residence hall even has maid service. All residence halls are staffed by 24-hour security staff, contain multiple resident assistants (RAs), and several halls contain faculty in residence. Unlike many other universities, NYU rooms all have their own bathrooms and thus no common bathrooms exist. Many residence halls have their own dining hall, and the university has meal choices to suit various diets. Almost all the residence halls have a laundry room that is open to resident students 24 hours a day.