When building a new home, interior door widths are one instance where wider is better. Building codes address door width, but codes are typically adopted on a local basis and may vary from jurisdiction to jurisdiction.
Take for instance a family that was moving a portable crib from one room to another–it measured 31-inches wide, fully assembled. You can bet they were glad to have opted for 32-inch wide doors!
Wider doors do require more attention in the design phase. But for ease of moving furniture, access with a walker/wheelchair, or just not having to turn sideways when entering the bathroom, don’t settle for less!