Passive solar and the masonry stove, of course.
It was 74 F in the basement by mid-afternoon. We don’t turn on the electric baseboard heaters unless we’re watching a movie so all of that heat came from passive solar. Amazing, huh? And it was a perfect day for passive solar: mostly sunny skies all day, from dawn to dusk–typical last winter but, alas, all too rare this winter.
Meanwhile, upstairs, it was cooking at 77 F. [Yes, I exaggerated and rounded up by 1 degree F in order to get the silly rhyme in the heading.] Between the masonry stove and passive solar, the temperature on the main and second floors was even higher than the basement.
Biscuit seemed oblivious to the verging on Bikram yoga studio temperatures. (Well, not really. They heat to an unbelievable 107 F, as I recall.) Mabs moved out of the sun and sprawled out on the hardwood floors by the kitchen, notably out of direct sun. I think he was too warm, but he is all black–and furry. We even opened the door to the mudroom in order to heat up the mudroom on the north side of the house, but also to let in the cold air that had been trapped in there for days. It’s a bit of a waste, but when it’s 77 F in the house thanks to sustainable heating sources (solar and wood), it doesn’t induce any guilt.