The Payback

Homeowners who undertake deep-energy retrofits are usually motivated by environ­mental or energy-security concerns rather than a desire to save money on their energy bills. These jobs are so expensive—in the range of $50,000 to $150,000 per house— that a homeowner would have to wait decades before the investment could be recouped. "In a retrofit situation, it can cost a lot of money to save a small amount of en­ergy," says energy consultant Michael Blas – nik. "Going from R-19 to R-40 walls or R-30 to R-60 ceilings doesn’t save a whole lot of Btu—and the cost of that work is potentially tremendous."

There’s no easy way to calculate the payback period for many deep-energy ret­rofits, in part because a major overhaul of a building’s shell inevitably includes many measures (for example, adding new siding or roofing) that aren’t energy-related. Although these elements don’t make a significant con-

tribution to a home’s energy performance, they may greatly enhance the home’s aes­thetics and value.

Those of us without a Midas budget will need to settle on a less ambitious approach to energy savings than a full-blown deep – energy retrofit, and that’s OK. Less expensive and less invasive retrofit measures, typically referred to in the industry as weatherization, have payback periods of 15 years or less.