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. 

NOTE: if you have rentals in California, be sure to buy the California edition because it is the most regulated state and requires a separate book.

Two completely separate things.

House has been on the market for quite sometime, originally at 349,000 now 299,000. old historical mansion, 3 bedrooms, keep up fairly well, with a separate entrance 3 rd for 1 bedroom apartment.