We are talking about service conductors, load side of meter to a MCB panel. which is located within a structure.....correct so far?? One run to the shop, one to a house.
Service conductors cannot be 'inside' a structure as they have no over current protection, with some exceptions.
Basically, in most jurisdictions, as long as you enter a panel with the conduit & conductors right inside the structure you are OK. Running the conduit & conductors within the structure without OCP is not allowed, unless you encase the conduit/conductors in 2" of concrete.
I'm curious why your dad said 'no way'??
