Wow, you'll have to PM their details as I have had just the opposite of luck in that regard.I may not explained it succinctly enough in my OP but regarding neighborhood grades- I just can't think of a situation where a school district can be a D/F and the overall grade be a "B" or higher. 

Whatever....Meanwhile, back at the ranch, congrats to the OP for knocking it out of the park.

(Sorry for changing the subject, OP)

AS for what to do with the equity the OP has.. that's all personal choice.. 

Depending on your market and ease of instillation, run the numbers as both coin-op in the basement or individual hook-ups (assumes you'll get more rent).Your CoC ROI is pretty bad at 5% (after reno).

It's incorrect and confusing to co-op the term "Cap Rate" to mean this, but...

The whole discussion hinges on protecting the 'very low rate' mortgage under your name (the OP). 

Sai,Before entering my current position, I spent the last 13 years selling niche products exclusively to community associations (HOA's, Condos, Townhomes, Co-op) all over the country. 

I am in the same boat as OP, except the cottage ADU is on the market as an Airbnb.

As I stated in my OP I have just begun to seriously start studying RE investing so I have not got into how to put a contract together yet, or even how to analyze a property to be sure it is a good deal.