Here is a link to the IRC - IBC Building Codes, https://www.iccsafe.org/codes-tech-support/codes/2... we do Modular and SIP Panel Production and these are built and placed on stem walls as the foundation. 

If you are purchasing anything which looks like it has been renovated it is a good idea to check permit history or at a minimum look at the electrical panel to see if there is a new signature on the box.  

@Ryan York I am curious what your plan of action is now that you have received some input from this panel of experts.

I've had GC's bid from 30k to 70k and of course the ones that big 70k told me to don't listen to the 30k ones.One GC said, Nope, this isn't a job I would take - you should get a licensed electrician (entire electrical panel is gone) and do the rest myself.I am not handy, but I haven't tried.

Depending on the  electrical work  you will need a permit (i.e. running new or replacing electrical lines) and/or an inspection (i.e. upgrading or installing an electrical panel). 

Dan, if you're looking for a 4-plex make sure it's already fire-coded or you plan for the expense. 4-units have to have a panel and that panel also has to have regular inspections so that's a potentially big up front cost (if no panel is there already) and an ongoing extra expense.

I always picture a solar paneled roof that I can have an office on the top floor wrap around windows and watch the sunrise on one side of my office and sunset on the other.

Roof, siding, windows, exterior doors, hvac, water heaters, electrical panels/wiring, main plumbing stack.

I can not remember the brand of electric panel in the house and it may need a new one for insurance purposes and it most likely needs a new hot water heater.

. ~ Most interior doors were trashed so we got these switched out with nice looking 6 panel doors.~ I always have an empty unit re-switched/re-plugged with the modern looking square outlets/switches.