Primary schools can be designed in a variety of sizes, configurations, and layouts depending on the school district and the program. It is fairly common for grades six in China. Students at this pre-adolescent age are becoming more independent, experimental, and temperamental. They have transitioned from primary school, where instruction occurs for the most part in one classroom with one teacher, and are learning to follow schedules and find their way to different parts of the building. The physical organization of the school needs to provide easy navigation that builds confidence without sacrificing safety and security. Elementary schools should be comfortable visually, acoustically, and thermally; they should have excellent indoor air quality; and they should be safe and secure.