There's probably room for more anyway.

Those are going to be my biggest questions when looking for something like this on or off the market.Thank you for the input. previous business owner and building owner has been practicing for a while and built this office for medical office ( receptionist and exam rooms ) with nice decorations.

I don't like to be any higher than about 70% all in, because there's no room for error otherwise.

This is a summary of learnings from a recent project I personally completed.  
Steps involved:
1. Buy a home with a large backyard
2. Get permits to build a detached ADU (DADU)/backyard cottage in the backyard
3. ...

Or renting out by room can be an option for better CF. 

:@Matthew Paul not if the oil tstat is located in the locked boiler room.

We suggested bug bombs in each of the larger rooms.

The manager is there from 2-5 weeks and he pays him a salary plus room and board.

You could also house hack and rent all the rooms out to friends, but some people would rather have their own space.

My sense is grand majority of MTR's are rented from tenants not in state or in the area for a showing anyway.