We try to find prospects that also have separate utilities such as electrical and less commonly separate water/gas.

And what is unhealthy about air from cooking unless maybe you have a gas range?   

No gas. 

If you have a pool will it be heated and if so gas or electric?

Less impactful but they also used 2 therms/day of gas (either long showers or used the gas fireplace while cooling to 61 degrees.In addition guest broke closet track and moved football table into the closet.  

The gas and electrical meters can be separate from the main house.

The time spent meeting pest inspectors, home inspectors, roof inspectors, HVAC guys, septic inspections, any contractors for work that needs done, photographers (paid by selling agent) signs and other marketing, Omissions and Errors insurance, MLS fees, NAR/CAR fees, car insurance, gas, only to have a deal fall apart over something.

Also, if the tenets already pay for their own electric and gas can you use RUBS (if leagal) for water and sewer?

I have a gas station in Los Angeles and it is one of the only gas stations within the city where not a single homeless person is at the pumps or at the door or on the lot asking for change.

If you can find a 4 family in MA with centralized heat (oil or gas) and knob and tube wiring you could get $60,000 from mass save for your project plus a bunch of free stuff.