Although a lot of attention is paid to building green houses, the biggest paybacks in terms of the environment and energy are from whole-house retrofits of older homes, two experts told attendees at the West Coast Green conference in San Francisco recently.

“That’s where savings are in terms of carbon emissions and efficiency,” said Larry Zarker, CEO of Building Performance Institute (BPI). But, he added, “That’s where we have to do the hard work.”

One-third of the 128 million U.S. homes that need improvements are 45 years or older, and an additional one-third are 25 to 45 years old, Zarker said.

Nevertheless, existing homes across the nation may not get the eco-friendly, energy-saving upgrades they need due to lack of contractor training, the former NAHB Research Center official said.

Zarker’s BPI trains, certifies, and accredits contractors and other businesses in auditing and inspection skills, including the Home Performance with Energy Star program. The other presenter, Bob Knight, is a co-founder of the energy consulting firm Bevilacqua-Knight.

A typical contractor-customer interaction focuses on isolated problems, such as weatherization, leaks, mold, and other conditions that can cause allergies, and goes from an inspection right to the sales contract. Part of BPI’s goal is to train contractors on a more holistic approach with homeowners.
 
Contractors need to educate homeowners about the building science that leads to the most cost-effective energy improvements, the presenters agreed. And stimulus package tax credits worth thousands of dollars may convince homeowners that whole-house retrofits are worth the investment, Zarker said.

Likewise, an independent, third-party quality assurance program verifying the upgrades is especially important if government incentives are tied to the work, the presenter added.
 
States are ramping up efforts to support whole-house energy-efficient renovations. In January, for instance, California’s Public Utilities Commission will pour $113 million into homeowner retrofit implementation programs, which include marketing, training, quality assurance, and documentation. California’s goal is to have 130,000 homes upgraded during the next three years.

“With the Public Utilities Commission, whole house is the word of the day. With changing a window we may get a one-tenth of where we need to go. There’s a pressing need for a much larger scale effort,” said Knight, later adding, “The key is to get volume.”

Leslie Mladinich is a San Francisco Bay Area-based freelance writer.