You might run into adequate HVAC capacity and needing to run additional ductwork (then determining a pro-rata billing set up perhaps) or even an additional unit with separate water meter just the same. 

Breakdown of the park:47 lots (6 rentals 15 owner occupied)21 filled17 vacant trailers (I have a crew that remodels trailers)9 vacant lotsLot rents: $298City water & septic - billed back to tenants. 

With mountains, water, and an outdoor community, it draws a vacation population.

The other concern would be if you pay utilities, this will increase water and electric bills.

Utilities you'll call and put in your name and water bill will stay with the property (at least here in Metro Detroit) but sellers will put some money with title in escrow in case they don't get a final water reading or pay that water bill before leaving. 

Case in point, we've provided a lot of parameters for our wholesalers and yet they still continue to bring us "great deals" that are not in our wheelhouse (i.e. mobile homes, properties not on City sewer and water).

.- The broker says that tenants pay gas & electricity, and the owner pays water, sewage, trash. 

The water meter is a single meter.

We are afraid to go in this much under water and don’t know if it’s realistic to expect appreciation this quickly to cover the negative equity. 2) Would you walk away?

Are they installing a siding block, mounting block on the house that’s waterproofed so water doesn’t run down the into your breaker box, behind siding and rot the substrate?