Your money is still in the property, and takes the form of bricks, siding, floors, etc... 

@Zoran Domazet & @Will Barnard - not an expert, but being in Florida (where sink holes are frequent) and seeing "polyurethane to fill a void" (polyurethane being an expanding foam with little load bearing capability) makes me thing that we are not taking about a small crack in the floors/walls due to foundation settling, but something more vicious.

I like Bozeman because I have seen 80's-90's vintage deals with classic vintage (formica counters, original vinyl floors, classic vintage fixtures, white/black appliances, etc.) trade for >6.25-7.00% caps going in with value add upside for those willing to hunker down and make upgrades in order to realize rent upside.

@Juan V Lopez doubt it would work, but you could try and go for a fixed percentage of revenue with a floor and/or ceiling.that combined with longer term could be intriguing if u were growing.

Cabinets were in, floors were done, it was just small things like carpet in the bedrooms, counters, and fixtures. 

I will be inhabiting the 3rd floor unit.

I could: a) open the wall between the master and 53 sq ft; b) make 53 sq ft a bathroom (much more money but could be worth it since there are none on 2nd floor); or c) l could leave it as a "bonus room". 

Overall, the property is in good shape but needs a new bathroom, kitchen, floors, and cosmetic repairs throughout.

Avoid wood or laminate flooring.

I believe in your case you can add a JADU if you split a portion of the main dwelling unit, up to 50% of the floor plan, under 500 sqft.