Or are you going after 40 unit mom and pop buildings?

My CoC return in STL is 10% now that the buildings have stabilized, it seems like the buildings are appreciating at an acceptable rate, and I have a team that I trust there (realtor, PM, contractor, lender). 

Would I be able to knock down and build a new home and once I sale, I use proceeds to pay off the first bank? 

I am going to build a house on it with cash and live in it.

Learn your market inside and out and build a team of people around you who can help you analyze deals and make moves.

I know there is a lot of variance, but what would be a good baseline threshold number to compare quotes for building a 5/5 house in Atlanta GA with average finishes nothing fancy?

The upside:  There is a lot of money to be made, potentially, and every door you add to your portfolio builds your company's value bigger and bigger (vs. sales, where it's a transaction and then it's over).

Original to the building?

It makes it easier (legally) to build an ADU and provide a means to rent it out or have family stay there.

I've had countless conversations with heirs who spent a long time trying to figure out how to make money off of land or buildings, but without experience, and never got anywhere a year later.