Upon entering the property, we have found that the hot water heater does not work, the flooring is all buckled up, the countertops are falling apart, no appliances, and the A/C Heat unit is not working.

What about heating unit?

Like @Bill Brandt had mentioned, the rental market was slowed for a few weeks, but it seems to be heating up quickly.  

What makes these ADU's interesting is that they seem to walk the line between residential lending, permitting of utilities, fees, but also have a commercial element as they are built as rentals.

Any decline would likely be offset by the market heating up for summer buyers.

Currently I am covering water and heat for both tenants but would like to bill the tenants for their separate usage.

There are older homes that have new electric, plumbing, roof, windows, heating, etc... 

Is there power to the building, has the heat been on over the past winters, i.e., frozen pipes, damaged walls, roof leaks, etc.  

But, I still had to keep the heat on, all the electric, and the water....

Once you get north of Brunswick and a little away from the coast, prices are really low, especially compared to Portland.Oddly, it's fairly common for rentals here in Maine to include heat in the rent, so if you're out in the middle of the winter and need to warm up, you know your tenants will have their apartments at a nice cozy 95 degrees.