I do remember that they put an access code at the main entrances and once you entered... you walked down old hallways that still looked like an old school hallway with the condo entrance doors to the left and right.  

He rents/rented a room off my home that has its own entrance (so no common access to my part).

And that is, finding a property with a detached garage or a basement with a separate entrance/exit and converting that space into an additional dwelling unit (called an ADU) which I can either rent out short term on airbnb/vrbo or longer term.

With separate side entrance to basement and a good potential for duplex conversion.

This property has a separate entrance to the downstairs unit and the space to add a kitchen.

I've got a home that has an unused 2 car garage with separate entrance that I'm looking to lease out.

MF would be ideal because you really aren't living with someone or looking for a SF with a separate entrance basement which would create the separation you desire I believe.

Same builder, same house, in same neighborhood for example could back to a busy main street in the entrance of the neighborhood, could face West where people prefer East facing, be the house that everyone drives by and lights shine in the front windows when you enter the neighborhood, could back to power lines in the back of the neighborhood, could be next to the community pool, could be on a corner with a bigger lot, and a host of other factors go into pricing....not just size.The 3 main sources that most sellers use for size are tax roll, appraiser, or builder's plan. 

We also built a small addition to accommodate a better entrance door and curb appeal.

Hi BiggerPockets Community, I am about to sell my first renovation project where I remodeled the basement into another living space (there is also a separate entrance to the basement).