This may be offset with the atypical fact that the tenants apparently pay for the heat.

For instance, how well do the walls insulate against heat & cold?

During closing the inspection came back with the following issues; related to the heater (3 years old, newer and running but HVAC guy going on Monday to try to figure out issue with it not heating correctly), electric (Zinsco, Electrician said should be fine but will give quote to fully test it), chimney (cracks in base of chimney on inside inspector said could just be from regular use, deciding whether to pay for additional chimney inspector), roof is less than 5 years old but does have some shingles that are raised, insulation is missing from the upstairs and insulation was installed upside down in the basement, other issues (toilets, fronts steps work not done correctly to code, tilework in shower, water shut off not in good location, etc.) and finally the upstairs has some structural issues with the upstairs sloping slightly downwards (only notice it in a 3 foot width) near the windows on the chimney side (I am waiting for the structural engineer report which I should get on Monday).

It is currently heated by and oil burning furnace.

Heat must be turned down at night and during the day if Tenant is absent from the dwelling or working all day.

an "emergency" element replacement with a tenanted building costs more than just putting a new one in before anyone is living there.

Of the 17 VMs I had two great leads, several prospects, and a handful of others that just wanted to see what I would offer.I have just under 30 days from now to sell the properties under contract, so my marketing is heating up: multiple posts on all the normal sites and bandits go out tomorrow night (Friday).

Water heaters are part of the real estate unless you are using a tea kettle to heat the water :)

Do holding cost include things such as electricity, water, heat, ect... if so/not how is this calculated?

The exit timing is a million dollar question.A big advantage in real estate investment over stocks investment is that you can make an exchange without realizing the gain.High yield properties such as apartment buildings might be easier to ride through the elements.