Splitting utilities in a 5 plex?

[Michael Vigneault]

I'm wondering if anyone has advice: The water utility is no problem - divide by # of people in each apartment, add into rent. Each tenant has his own electric bill.

Gas is the issue - only 3 apartments have gas, all w/ different appliances. One unit has 2 gas heaters. How can I determine how much to add to the rent amount? Add the average gas bill into all apartments for simplicity or only divide the amounts among the 3? How to do that fairly?

I've been searching for TX rules for utilities, but haven't had any luck.

Thanks for any input!