Radiator heat piping? 

I would like to separate the heat for each unit so each tenant would be responsible for paying for their usage.  

but for your own, personal, investment and DD purposes, I agree an analysis like what you describe can be helpful on the LOW end in a heated market.  

The rest of the renovations are all manageable for us-  New kitchen, new heating system ( ductwork all done), flooring and paint, among other items.

What were were planning on is stating in the lease how the AC and heat would be programmed automatically.There is a gas "wood stove" to help heat the basement unit that the tenant would have exclusive control over.

As well, and assuming necessary, once done, you can advertise this upgrade and the positive resulting heating and cooling bills in future marketing when the need arises.For straight rentals (not a property sold via Lease Option, CFD, or other Owner Financing), I never pass large expenses on to my tenants (pretty much anything over $300, unless their fault), but assuming this is a defect or need that I did not see in my pre-purchase home inspection report, I will just deal with it out of my own pocket and earn a bit of positive "good landlord capital" in the process.Good luck with it!

@Patrick Donnelly yes there certainly are great opportunities in SATX, but the market is also starting to heat up more, especially over the past few months.

Yes this is normal, the same people to replace a propane water heater are the same people getting everyone ready for the heating season.

Major expenses: roof, electrical, heating and cooling, foundation, plumbingIt really depends on the individual property and what you plan to do with it.

I called several plumbing/heating companies and many were booked until next week.