Shared laundry may be unavoidable depending on the size of the home;   if the ADU is a smaller one is probably a safe move to make laundry free but if you are considering a large (2 or 3br) ADU you might want to think about metered laundry (coin op or something) just in case you get an occupancy-limit sized household.I don't know if they would allow it for an ADU vs. a real duplex,  but the ability to add a second electric meter and breaker panel would be a good way to prevent issues with excess utility usage (you could bill back or just require tenant to get the electric service in their name) - even without that there are submetering options.   

You can look on CCAP (circuit court for your county) and pull up distressed sellers--like foreclosures, probate, skip trace then call them.

This can be a deal breaker with a large mortgage.

For example, my city requires 12-2 electrical or higher everywhere; it doesn't matter if you are running one single circuit to serve a 1/2 amp stove exhaust fan, you cannot use 15A breakers and 14ga wire anywhere.

That's a deal breaker for those of us looking to scale a cash flowing hold portfolio :(

Check the breakers. 

Oh, if you don't live near one the shipping is a deal breaker!

http://www.businessinsider.com/the-inspiring-life-...There is no short cuts in life that won't come back to short-circuit your success.  

The meter base has room for a 6th meter already,  adding the plumbing and breaker panel would be relatively easy (crawlspace access under the entire lower floor where this space and the meter base/laundry area are) and adding egress windows is also possible. 

it cost about 150 to have a electrician run a 240 from your breaker box.. its like setting up for a dishwasher .