15 engines

Insulation & Envelope

Attic, wall, and window paybacks by climate zone, and which envelope upgrade actually pays for itself before a bigger equipment purchase does.

Envelope work, insulation, air sealing, and windows, competes for the same budget as bigger equipment purchases, and it often wins on a pure dollar-per-dollar basis despite getting far less marketing attention. These engines price attic, wall, floor, and window upgrades individually, plus how climate zone changes the payback on the same project in a different part of the country.

For the ideas shared across every Insulation & Envelope engine, see Why the Envelope Can Change Later Economics.