I'm from NY but heating costs (gas) are similar throughout US, more or less. 

( owner or tenants ) Electric and heat paid by ?

Can I measure the outside of the house and exclude any non cooled or heated areas?

The ONLY hesitation I have is that the unit has electric heat.

Hi all,What could cause a sewer smell to come out of an air conditioning/HEAT vents?

You can call utility companies to see whether the heat is on.

There are limited funds in my account for this house ( I don't want to have to dip into my personal funds ) and we have continued to give the extensions reluctantly when they have asked  but now I feel the other party should pick up the costs going forward... why should we continue to pick up the cost of our mortgage and heat and such through no fault of ours.

For $1300 extra that I'll spend on house wrap and labor, I don't want to take the risk.I have not built multi family yet from scratch, but my company has gutted and remodeled several buildings in uptown Mpls that were converted into condos.I know of only one multi family developer in the Twin Cities that understand the concept of exterior foam insulation and reduction of thermal bridging who uses zip wall system.Yes, you pay more upfront, but if you plan to keep the building for 5-7 years you recoup the entire cost of zip wall system by paying less for heating and cooling.In commercial construction, smart developers used exterior foam insulation since 1980s, I had a building in Hopkins that had that.

If you also have central air conditioning, the furnace installer can plumb the inside air conditioner drain (A-coil drain) and the furnace drain into the same pipe.Sometimes there are federal, state, or local rebates or tax credits for adding insulation. 

There is a valve on the boiler system we keep because  we have had one fail, there are five of them and we had to wait on the replacement part for this one when it failed meaning heat did not travel to that zone.