Or a regular house where you rent out the basement and it has its own entrance.   

It was my entrance into the Philadelphia market that was a rude awakening.

An alternative way to design the project, would be to put common upper floor walkways to the entrance of each unit (called "catwalks") and have all units served by just one elevator.

It has since become defunct.There is a pretty decent clubhouse at the entrance of the subdivision that is vacant and apparently for sale.

And going to the courts to petition an emergency entrance with the “police” would take days.

Has anyone had success in converting the primary bedroom and bathroom suite into its own unit and requiring tenant to access unit through a private entrance (backyard or side yard entrance to bedroom)? 

Then, you need to develop criteria for a series of "steps" (properties), with each "exit" from one property becoming the "entrance" to the next property, that leads you through your milestones and to your goals.  

Common hallway repairs were staged so that they could have access to one entrance to their apartment. 

Though if I go that route of adding the master bath, there is the potential of giving the master it's own private entrance, private outdoor space, and turning it into a med term rental.

In my area, we get snow and ice tracked into the building so we use a large, commercial grade mat for the entrance.