The Efficient Home: heat, cool, and power for less

Before you price a bigger furnace, price attic insulation. It's the unglamorous upgrade that shrinks every other number on this page — the smaller heat pump, the fewer mini-split zones, the furnace that finally cycles the way it should.

These calculators price the whole comfort stack in the order that saves the most: seal the envelope first, then size the equipment to the tighter house, then add the extras that stretch it further — a whole-house fan for the shoulder seasons, a pellet stove for the room you actually live in, and backup power for the day the grid quits.