IRC:Chapters 26, 27, 28, and 29, cover plumbing code for types of shut-off valves, depending on the type of service, shut-off requirements, and placement, including access.
Process/Skill Questions:
Where are main shut-off valves typically located in a house?
What size is the main shut-off valve in a house?
What types of materials are used in the construction of the main shut-off valve?