The world’s greenest winery through LEED and the living building challenge

In 2006, a fire severely damaged the Silver Oak Winery in California’s Napa Valley, destroying its facilities and an estimated $2 million worth of wine.

For this longtime family business, the immediate aftermath was emotional, as the owners surveyed the damage and absorbed this grievous loss. But the family soon realized that the fire had given them an opportunity to rethink their business and bring a proverbial phoenix out of the ashes.

The winery’s first major decision after the fire was to rebuild as soon as possible, and the second was to do it sustainably. The result of this effort was a redesigned facility in Napa’s Oakville region that achieved LEED Platinum certification, the first production winery in the world to earn that status. Now, a second phoenix has risen to match the first.

Silver Oak’s newest facility sets a new standard of sustainability for the wine-making industry. The brand-new winery is in the Alexander Valley, a viticultural region in Sonoma County that has become particularly well known for the quality of its Cabernet Sauvignon and Merlot. Employing solar power, efficient LED lighting, and a water-filtration system, the winery is also on track for LEED Platinum certification—becoming only the second winery to earn that status after Oakville. The project is also aiming to earn four out of seven possible “petals” under the Living Building Challenge certification process: for energy, water, health and happiness, and beauty.

Silver Oak began as a partnership in the early 1970s and has been under the sole ownership of the Duncan family since 2001 (the family patriarch, Raymond Twomey Duncan, was one of the original cofounders). The winery is now led by CEO David Duncan and Executive Vice President Tim Duncan.

“Being stewards of the land, taking care of our vineyards, and trying to do all we can to protect what is our only home is something that is sort of in my heart,” David Duncan says. “Water conservation and the lack of pesticide usage, all those things that go into what the general public thinks about sustainability, fit right in with what we do.”

Sagan Piechota Architecture led the building design, with Cello & Maudru Construction serving as the general contractor. In addition to sustainability and functionality, aesthetics were important to Silver Oak. Plumbing and catwalks were laid out in a symmetrical, pleasing way, and the facility increased daylighting through skylights and other measures. Reclaimed redwood from 85-year-old wine-fermentation tanks was reused as external siding.

For task lighting, technology has advanced remarkably: Energy efficiency that would have been difficult or cost-prohibitive for a winery operation now is doable. Every task light in the facility is LED, for example—which would have been three times the cost just a decade ago, according to Duncan. The bulbs need to be changed so infrequently that it’s almost a nonissue going forward.

Solar has similarly become more cost-effective. “Ten years ago, solar panels had a payback of seven to nine years,” Duncan says, “and we think these are going to be more like three or four [years]. Things have advanced that much in a short amount of time.”

Sustainability, for Duncan, is first and foremost about wine quality. It takes a lot of water to produce wine, so water conservation and reuse are of paramount importance. The team worked with TEP Engineering to design a central hot-water system that uses solar thermal energy and CO2 heat pumps to provide heat for the domestic-, production-, and recycled-water systems, in addition to the warm-glycol system, which helps control wine temperature.

“This is the first project to my knowledge that uses recycled hot water, which is ideal for winery-production facilities because it typically requires around 6–14 gallons of potable water to produce one gallon of wine,” says Andy Souza, PE, LEED AP, a plumbing engineer with TEP who recently was named as one of AutoCAD’s “35 Under 35 Young Designers.”

“Silver Oak is attempting to reduce this winery’s production-water use by using recycled water for initial barrel and tank washing and floor cleaning, to get the production potable water requirements down to two to three gallons to produce one gallon of wine.”

The centerpiece of the site’s water-management system is its membrane bioreactor (MBR), which is a series of settling tanks and membrane filters that gradually remove particulates from wastewater created by the wine-making process (not sewage). That allows it to be reused for various functions in the winery, including flush water. Rainwater is captured and funneled through the MBR, as well.

“Money is a resource,” Duncan says. “Green at any cost doesn’t prove anything.” Among other decisions, computer modeling in Revit helped the bottom line, allowing the team to identify and address problems onscreen rather than during construction. “We fixed many, many problems on the computer that normally you would fix in the field,” he adds. “We think it saved us hundreds of thousands of dollars.”

With so many elements, the team also used BIM 360 Glue to ease team collaboration. “We used that in larger subcontractor-coordination meetings to look at the scope of work and how it pertains to schedule,” says Adam Katz, a product engineer with Cello & Maudru. “We have also issued iPads to all our foremen and superintendents and used those with 360 Glue for reviewing the model in the field, in real time, to look at assemblies and help coordinate subcontractors.”

Another innovative feature was the use of reclaimed denim as insulation material. “All the insulation in the office spaces are recycled Levi’s, which is actually kind of fun because I pretty much only dress in Levi’s,” Duncan says. Modeling helped the team to understand the different dimensional properties and R-values of denim insulation versus standard fiberglass or foam insulation. “We have used the software coordination to express those different thicknesses,” Katz says, “and how layouts and different construction assemblies come together in a nonindustry standard way.”

“Our building should be obsolete from the minute we finish it,” Duncan says. “Because the next person who builds a winery project like this can learn from us and do it even better.” Based on Silver Oak’s sustainable track record, there’s a good chance that the next winery that does it better will be Silver Oak itself.