If you build a detached ADU you are not necessarily constrained to 50% of the square footage of the main dwelling.

So it is zoned RM-4 which allows for multiple dwellings so that is good. 

Starting over with my first rental in Florida, getting a tenant who pays the first month's rent and that's all the money you get unit you get them out...The next new Cares act that they are working on right now may include more of the same: >>CARES Act Section 4024(b) prohibits landlords of certain rental “covered dwellings” from initiating eviction proceedings or “charg[ing] fees, penalties, or other charges” against a tenant for the nonpayment of rent. ...

The dwelling, down payment, interest rate, rental type, preferred renter profile, and more are all important elements of the model.  

Another way companies handle the insurance on that situation is a Vacant Dwelling policy with Renovation.

Or take it thru your dwelling? 

I bought a duplex years back as a primary residence and a rental with the other unit. 2 years later I had to refinance to get my ex's name off of it and since it was a "multifamily dwelling" no bank would loan a single income borrower more than 75% LTV.

A lot of people on larger parcels have a need for a shop space and would maybe want that instead of another dwelling unit.

One of the categories says DU which is legal dwelling units.  

The plan would be to combine the first and second floor units on the left side of the building to form one upstairs/downstairs dwelling, and then do the same on the right side of the building.