How to find utility cost before making an offer?

[Ken P.]

We're considering making an unsolicited offer to purchase an apartment building.  We know what the rents are, what the vacancy is, what the competitive rents are, have estimated per-unit and site rehab costs, after-purchase taxes, etc.  However, this particular complex includes heat and water in the rent, which means utilities are a significant portion of the operating costs.  If we are successful in acquiring the apartments we'll switch to RUBS because the market supports it and competitors use RUBS, but to make our offer we need to know utilities.  Is there any way to determine utility costs beforehand; e.g., calling the gas company, etc?  Gas is serviced by DTE or Consumers Energy (southeast Michigan utilities).