To the naked eye, Tanya Narath's northwest Santa Rosa home seems the picture of energy efficiency.
It's got solar panels on the roof, double-paned windows throughout, newer appliances and solar tubes drawing in natural light.
But when home performance expert Mike Fitzpatrick recently conducted an energy efficiency test on the 18-year-old home, he made a troubling but all-too-common discovery -- the 1,500-square-foot structure leaked like a sieve.
When Fitzpatrick, a project manager with Pinnacle Homes, used a powerful doorway fan to create a vacuum inside the home, the chilly morning air rushed through poorly insulated areas in walls, light fixtures and appliances throughout the home.
The solar tubes in the ceiling, which Narath and her husband Tim Sweeney had installed to reduce their energy bills, turned out to be black holes, literally. On Fitzpatrick's thermal imaging camera, the tubes appeared surrounded by ominous black rings indicating cold around was pouring through them.
"It's horrifying, isn't it?" said Narath of the images. "I guess this is why it feels like the house loses heat so fast."
But Narath's problem is an opportunity for the county's battered construction industry.
Construction companies, pummeled by the collapse of the housing market, are seeing modest but important signs of growth thanks to increasing interest in energy efficiency programs.
Just like drivers are flocking to hybrids, homeowners are more willing than ever to pay for home efficiency upgrades, spurred by novel government incentives and increasing concerns about greenhouse gas emissions.
"We're really thinking about our carbon footprint and how we can get it as close to zero as possible," Narath said.
In pursuit of that goal, Narath has hired Pinnacle Homes to manage a home energy retrofit that will replace her aging furnace, install new duct work, seal up those drafts, and blow in a new layer of attic insulation, among other things.
When completed, the $41,000 in upgrades should slash Narath's gas bills by 75 percent, make the house more comfortable, and improve its resale value, said Craig Lawson, president of Pinnacle Homes.
The project is just one example of how the Sonoma County building industry is transforming itself to take advantage of the potentially massive new market created by the push to improve the efficiency of the county's 230,000 buildings.
Since housing construction has ground to a virtual standstill, builders are reinventing themselves, focusing instead on rebuilding existing ones to make them as efficient as possible.
Companies like Pinnacle Homes, which since 1993 built dozens of high-end houses in exclusive neighborhoods like Santa Rosa's Skyfarm, were forced to shift gears in 2006, when the market started to collapse.
As it scaled back operations, the company shrank from 25 employees to just seven earlier this year. As Lawson and vice-president Dick Dowd used the down time to take a closer look at green building techniques and certifications, they realized just how big an economic opportunity the energy retrofit market represented.
"This is a pool a lot deeper than people think," Lawson said."
They've since hired an additional five people and now see "home performance" as a permanent division of the company.
Sonoma County homeowners will need to spend an estimated $1.5 billion over the next five years to button up their homes enough to meet the county's carbon reduction goals, according to the county's Community Climate Action Plan.