Also, one of the bedrooms i hope to add will be in the basement, which is already finished and has a separate egress.

In this case I would have the tenant remaining sign a new lease with the remaining term of the original (unless they wanted a different length)And then I would write a separate half page document cancelling the previous lease and have everyone one sign it.This scenario is why I like all parties to qualify financially if there's unrelated people on a lease.

It isn’t a separate item.  

You will need a Residential Single Family Purchase Contract (assignable or double close), then a separate assignment of contract interests.

So my parents are separated in age by 14 years and my father's health is declining a little more rapidly than expected. 

@Natalie Kolodij: I m curious, are detached ADUs always treated as a separate unit vs primary residence unit at the time of sale?

@JB Gough 1- are these two homes on a single lot, or each on separate lots?

@Jason Appel I view deal criteria and a checklist [I call this due diligence] as two separate things, and I use the same system for every single deal.

I didn't want to have to have separate apps for rent and accounting and expenses.

I get access from his road grandfathered for the far side of my storage units.We both negotiated doing the electrical for our own properties and cut the line separating our service.