The Efficient Home: heat, cool, and power for less
By Dan Whitlock, Home Projects Editor · Updated July 2026
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.
- 1Attic Insulation cost
$1,500–$5,000
blown-in fiberglass or cellulose in a 1,000 sq ft attic, professionally installed
- 2
- 3
- 4
- 5
- 6
- 7Whole House Generator cost
$5,000–$20,000
14–20 kW standby generator, natural gas, automatic transfer switch, installed
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How these numbers are compiled
Every range is the typical installed cost most homeowners pay, cross-referenced against published 2026 cost guides and contractor databases, then pressure-tested against our own calculators. They are planning figures, not bids. Read our full methodology →