An architect, insulation installers, door and window salespersons/installers, and a mechanical contractor are in a classroom together, and the instructor asks: “Should you upgrade the building envelope or replace the heating and air conditioning equipment? You can only do one or the other first due to budget constraints.”
Only the mechanical contractor says HVAC equipment first and everyone mocks that answer. The energy audit instructor says, “Of course you’d say that — you sell HVAC equipment. Care to explain why you think you’re right?”