Class 9 buildings are those that are open to the public. Class 9 buildings are divided into three sub-categories: Class 9a, Class 9b, and Class 9c. Class 9a buildings are often hospitals, which are referred to as health-care buildings in the NCC. They include nursing homes, long-term care facilities, residential care centers, and other medical institutions. Class 9b buildings include schools, churches, theaters, museums, government offices, laboratories, research centers, universities, and other institutions of learning. Finally, Class 9c buildings are businesses or commercial establishments such as shops, stores, restaurants, bars, hotels, motels, casinos, theaters, or any other place where people can work or live. In addition to these categories, Class 9 buildings may also be sub-divided into different types of construction. Class 9a buildings can be either freestanding or attached. Freestanding means that they are not connected to any other structure. Attached means that they are connected to another building or structure by an interior corridor or hallway. Examples of attached buildings include clinics, libraries, police departments, and courts. Class 9b buildings can be either new or existing. New means that they were built within the last 10 years. Existing means that they were built before 2010. Class 9c buildings can be single-story or multi-story.