A home distribution box should match your circuit count, rated current, safety rules, and future power needs. A good choice has enough spare ways, suitable RCD or RCBO protection, surge protection where needed, and an enclosure approved for the local installation standard. The. An indoor distribution board (also called a domestic DB, house distribution board, or indoor DB box) is a standardized electrical enclosure installed inside buildings to safely divide incoming mains power into multiple protected branch circuits. I've been in those shoes - staring at spec sheets, worrying about.