A 'pre-fab' (fixed in place mobile home) requires permits for the electric service, and HVAC that is field installed. The actual 'unit' is not inspected. Bldg requires permit for tie-down, skirting, stairs/landing and the pad. Plumbing requires water & sewer connections.
Modular homes require the same, plus any work in the grade level and exterior. We do inspect the splice points, and any field modifications that may be done.