I should clarify, the property currently isn't livable...no mechanicals and electric isn't wired to the panel, so not sure if that makes a different with land contract vs traditional seller financing.

I realize there are city and zoning regulations, permits, converting the hvac systems/water meters/electrical panels, etc.

Exterior/Interior paint, installed A/C unit, New electrical + panel, Appliances, Vinyl flooring throughout, bathroom upgrades What was the outcome?

Panel boxes for both units are in the basement. 

The way you construct the building, how high it is elevated, what is in the lower levels, does it have flood mitigations like breakaway panels, etc. all will impact the eventual rate for the Flood Insurance in the National Flood Insurance Program (NFIP).  

There might be a panel hidden in one of the apartment closets that gives you access to the main pipe that is capped that drains the shower and the sinks.

Other things they look at is emergency lights, loose railings, chipped paint, cracked walkways that may be a trip hazzard, self closing self locking doors, fire retardant paint on wood panel hallways just to name a few.. 

updated appliances, pulled up linoleum and refinished floors, added electric panels in units, and added instant hot heat/hot water for units Lessons learned?

new HVAC, electric panel, recessed lights, added bathroom, tiled bathrooms, opened up kitchen, new cabinets and appliances, granite counter tops, refinished floors.

It has solar panels and currently producing enough energy where the electricity bill on this 5,500 sqft home is only 25/month.