RUBS in Washington State

[Jonathan McKay]

Hello, I'm looking at purchasing a 10 unit apartment in Spokane Washington, but it has three shared water-boilers for all of the units. In order to make this deal work, I would need to be able to charge back the hot-water costs to tenants. Does anybody have experience with RUBS in washington state? Is it allowed? What contract language have you used / RUBS company did you go with? 

Thank you all!