There are prefab firms that make a 2 or 3 story structural column with the fusebox, water heater, vertical plumbing and wiring conduits, drains, sink toilet and

There are prefab firms that make a 2 or 3 story structural column with the fusebox, water heater, vertical plumbing and wiring conduits, drains, sink toilet and shower hookups, and spools of wiring to be pulled through walls. Almost no electrical and plumbing work needs to be done onsite.