Perform your make, size, square footage, condition, and amenities adjustments compared to the subject home, then look at the sales values over the past 12-24 months to try to find past year's sales in order to gauge past-to-present values and market direction.

Around me, 2-4 unit houses sell for less $/ft2 tha SFH, depends on the exact area, but generally 15-20% less $/ft2.The builder is offering what for that price in terms of sq footage, beds, baths?  

:-) @John Hickey John, so based on your experience of $11,000 for the 1600sqft home, perhaps mine (due to the much larger square footage) may be closer 18k :-O  Despite the cost, upgrading it would make me feel better and safe when I sleep! 

In other words, comparing ranches to ranches, capes to capes, etc; keeping the square footage of the comparables to plus or minus 20% and BR and Baths similar.  

@Michael Lewis what’s the square footage like?

The Estimation means nothing if I don't know the square footage.

Assuming your doing a typical Assignment of Contract and not Short Sales or any type of seller carry deals, you can start with a list of Absentee owners for whatever area your targeting.List source and Mellisa data both have lists that can be ordered with your pre-determined criteria such as year built, square footage, lot size, tax assessed value, etc.

You should certainly be able to get $1100 if not more in rent, given the size of this property and the square footage.

The complaint states surveillance footage showed a man parking, exiting, and then catching a bus.

I am wondering what all you ADU property investors are doing to evaluate adding the unit in an area that has no comps with an ADU or comparable sq footage.