My investment condo's HOA fees are distributed based on square footage, bed/bath numbers, and whether the entrance is private or shared.

The townhouse I recently purchased was the model unit for the entire complex and the contractors converted the garage to an office/den with a window and an exterior entrance.

Even better a sperate entrance to the basement is already in place. 

The second appraisal also approved its value in condition of “removing the front door (there are two doors at the entrance to show duplex) and kitchen on the second floor.”

An accessory dwelling unit may be designed to be located within the single-family dwellingwith a separate entrance or in a conforming accessory structure; however, it may not belocated in a nonconforming accessory structure or structure made conforming as a resultof a variance.

If yes, I've created an exhaustive checklist in irder to 'reverse engineer' the property, debt and title.After determining that the opportunity has merit, you need an entrance (and exit) strategy.If you are trying to buy the asset (the property) then you need to find someone who has the ability to pass title to you, either owner or the person in charge of their estate, if deceased (or conservatorship, if owner has diminished capacity). 

They removed the door and steel frame of both front and back entrances, painted them to match the rest of the bars, and rehung them.

They will not be using the same entrances, bathrooms, etc.

I'm guessing it has to be within the existing home, has to have a separate entrance, a bathroom, bedroom, living room and kitchen?

Go to Home Depot and post on their board ask if you can leave flyers or a large print ad near the entrance/exits or hand out flyers to contractors, roofers, etc.Maybe your numbers (ARV, repair costs) need to be adjusted?