How to handle shared Washer/Dryer yet utilities assigned to different units

[George Fleming]

I have two units separately metered and we are installing a shared washer and dryer. Logistically, the water and power for the dryer would come from the smaller one bedroom and the washer power would come from the 2-BR. How do I not make this fair yet not complicated? There is not "house" power or water metering. Part of me doesn't even want to mention the question of who is paying for the W/D utilities but I need a way of discussing this and making this fair given it's shared and usage could greatly vary. And what if the 1-BR unit doesn't even do much/any laundry yet is assigned most of the utilities? Thanks for any guidance!