Last Year I bought a 4 family property in AC.  3 of those units get their heat from one furnace.  I had several HVAC companies give me estimates for installing a separate furnace for each unit and the cost would be in excess of 30K.  Now I am about to close on another 5 unit property where again all units are heated with one furnace.  I would like to know what other investors have done to take this heating expense off their plate?  The tenants of the 4-unit all had their leases done by previous owner and heat was included as part of the tenants expense.  That owner would just billed them directly for the heat and cut it 3 ways.  The 5-unit are all on a month to month but the owner covers their heat.  I want to find a solution where I can bill them without having to always fight with tenants every month for the amount of gas heat they have to pay.  Can any one who has ever been through a similar situation tell me what steps you took to solve such a dilemma?