Single Family with In-Law Suite(utilities)

[Juan M Restrepo]

Hello everyone, 

I currently live in a single-family home with an unfinished basement. The basement has its own independent exit so no need to interact with the top floors. The plan is to build an In-Law suite and rent a house similar to a duplex. The top and bottom units would have their own laundy. The utilities are NOT separately metered as Is a single-family home. I also live in Johns Creek, Ga. The basement could rent for $1200 without including utilities. 

How would you bill for the utilities?

I can add a premium to the rent, but I have noticed that when tenants do not pay for utilities they do not care about wasting them.

Can you add an additional mailbox to a single-family home? 

Thank you guys for the answers.