Frame, insulate, plywood, panel.
No,I build a 2x4 frame,insulate it and cover with plywood then bolt the panel to that. No need to add drywall,that was law a few years ago but not any more.When installing a new breaker panel does anyone here sandwich a piece of drywall behind it. (5/8 fire ******ent). E.g. onto concrete basement wall - panel then drywall then plywood to wall.