Junction Box Inside Wall

[rayworld]

Saw a show on DIY where there was a junction box installed inside a wall flat against the plywood and butted against the side of a stud. The builder said this is against code. Why?

[Richard Moore]

All boxes must remain accessible. You say "inside a wall". If this was going to be buried by the drywall, then it would be wrong.

[rayworld]

Makes sense. Thank you.