I'm fine with doing some minor fixes and improvements to a property: Adding overhead lighting/fans, better flooring, maybe redoing a main bathroom.

There is roughly $20,000 left in rehab including windows, floors, a new kitchen and bathroom. 

It may be best to partner with someone that has done one before or somehow is a local expert on lot splits.If you can add a bathroom into existing space on high cost property it can add a lot of value.  

As someone who did something very similar to this for the last 2 years - rented out my 2nd private bedroom and bathroom in my apartment (rental) furnished to traveling professionals and medical students - I think it's a great idea! 

Originally posted by @Eric Mayer:When you have 50+ doors or 100+ doors, would this even cross your mind to worry about?

This single-family residence spans approximately 4,250 square feet and features 5 bedrooms and 5 bathrooms.

Additionally, I would like to attempt to do the process Owner/Builder with subcontracting work out as well as doing some of the work I'm comfortable with (I have some experience with bathroom & kitchen remodeling an am not new to the construction industry).

I currently own a 2 Bedroom / 2 Bathroom Apartment.

Built in 1961, this residence offers 4 bedrooms and 2 bathrooms within approximately 1,500 square feet of living space.

Yes, long-term rental clients sometimes don't want short-term rental next door to them, but you are the owner and landlord and set those expectations up front so it's on the table before they lease.