Los Angeles - Renting out in-law suites - Central heater/AC or mini split unit?

[Sarah Wang]

Hello friends, I'm planning to build and rent out a 500sft in-law suite, It is attached to the main building and I have existing duct to the rooms. But we usually turn off the AC/heater at night, not sure if it will be a problem for the tenant to share to central AC with us, so I'm thinking about use a mini-split unit for the in-law suit. But we are in Los Angeles county, energy bill is not cheap, should I worry about the tenant use the electricity? what is a good way to keep my energy bill under control and split the bill?  Thanks!