This standby generator will run on either natural gas or liquid propane.
This 076180 model generator have a decibel rating 66 (dBA) at 7 meters from the generator.
It will depend on local codes. Also if it is connected to two homes, it might not be able to fully power both homes.
69 dB at 23 ft. (7 m) at no load and 70 dB at 23 ft. (7 m) at normal load. For further information please consult your operator's manual under specifications.
This stand-by you have referenced in your inquiry has the capabilities of using both LP and NG the rating for fuel consumption (Cubic Feet per Hour @ 1/2 Load)=2.9 Gal, per hour.