Quote from @Richard F.:
Aloha,
You do not mention anything about the quality of insulation currently in place, and options to improve it. Also, how are your windows? Separate storm windows? Well sealed? 3rd story, converted attic? Is there ANY insulation up there?
If this is a long term hold, strategize to make the right kind of repairs and improvements that will pay off long term first, figure out the money part second.
Good point about the insulation, the windows in the house are the original wood double hung windows with the strings and weights, and storm windows on the outside. We're going through and refurbishing each window by replacing the strings and weights, coating with coverstain and painting, which has been working great. The 3rd floor was originally finished so no conversion, but there's two small access doors on the knee walls on both sides where you can see there is in fact ZERO insulation between the roof trusses. We're going to insulate those spaces and seal around the windows well, and install the furnace. Should make for happy tenants!