Sorry, the coop and shed windows. House has double pane windows. We planned and built it ourselves, after living in enough dumps to know what we wanted, and we put our money into insulation and efficient heating. Not even -40 chills the indoor air.It'd be nice if you could still find the old storm windows with the tabs on the top that fit over hooks on the window frame. I guess that double pane windows made them obsolete. I take it your house has single pane windows.
We've got propane radiant heating in the floors, along with some regular radiators upstairs.