if the zoning and permit in your area work then its worth it.

Aside from permits and zoning, what are some other considerations I should think about or issues you might have run into?

Best to work just outside of Nevada City/Grass Valley though from a permit cost and restriction perspective.

Oh I didn't look closely enough - you're right of course, you should go back in and edit the report to reflect more realistic refinancing at 75%.Unfortunately, the calculator doesn't cover every possible financing situation, but the BRRRR calculator does let you enter loan information for the original purchase as well as details of a new loan for the refinance, so you should be able to edit the report to reflect the initial hard money loan component you mention.I went into the BRRRR calculator and tried to recreate your report but adding an initial HML with 30% down at 9% and with some points and fees, rather than a cash purchase, and it certainly didn't look as good at the end.

I’m curious as to some insight community may have with regard to how the investments can be negotiated using the resources of the company I own (i.e manpower, equipment, Managment and legalities (permits,etc) has at its disposal.

You should consider the permitting process wherever this is, because it's entirely likely that everything mechanical will end up having to go through a new permitting process more or less the same way as a new build.

The zone will tell you what residential uses are permitted on the property. 

 I'd suggest contacting the county code enforcement office (they issue building permits) and ask about the rules.

I am thinking perhaps lease the land and help the local tenants out with finding the financing, planning, permits and utilities.

@Pasquale Zingarella Ask the Planning Department if they have a Special Permit process or Variance process that you can go through to try and add the 5th unit.