“You don't get carsick do you?” The question comes from David Warner, at the wheel of his white Toyota Prius. The answer is unclear. We are on our way from his office in Marin County, north of San Francisco, to a jobsite meeting in the hills above Napa Valley. This is an important project for an important client, and we are running late. The narrow asphalt winds through a chain of S curves, and Warner pitches the little hybrid into the turns like a Formula 1 car. But our rate of travel seems to match Warner's metabolism, the sun is shining, and late or not, he's having a great day. “The edict on this house,” he says, “is to be greener than we've ever been before.” That is saying a lot, because Warner's company, Redhorse Constructors, has been at the leading edge of high-end, green custom building for just about as long as there has been such a thing.
The Napa house's exterior walls will be built of earth excavated from the site—in a precise mix with sand and high-fly-ash-content cement—shot to 18-inch thickness from a Gunnite rig against open forms, some of them 12 feet tall. All the wood used in the building will be either salvaged material or certified by the Forest Stewardship Council as sustainably grown. All sheet goods will also be FSC certified. The building will contain no pressure-treated material, not even for the sill plates, which will be salvaged redwood. The interior climate will be conditioned by a geothermal heat pump—15 wells, 250 feet deep, have already been bored into the hillside site—via heated and chilled floors. Powered by a 32-kilowatt system of 180 photovoltaic panels tied in to the local electrical grid, the 8,500-square-foot house will consume as much non-renewable energy as a conventional building a fraction of its size. Battery backup will allow it to coast indefinitely during power outages. The jobsite itself is pretty green, too. The crew separates all waste material—wood, concrete, plastic—for recycling.
Warner races through the list of features, which by now represent something like a standard spec for Redhorse projects. But by nature Warner is always focused on the next thing, and today's next thing is paint. “We're creating our own paint line for this project,” he says. “We were trying think of the most benign, groovy stain we could think of, and we came up with iron oxide.” Rust, that is. “It will be on the concrete and wood as a wash,” he says, where it will make a nice, subtle contrast with the buff-colored earth walls. Much of the world's commercial iron oxide comes from Australia, Warner explains, and transporting it all that way entails an environmental cost that would cancel out any green points earned in using it here. “So we're extracting iron oxide from the scrap steel on the site.” Behind a storage container on the site, his crew has fitted an array of plastic barrels with a recirculating pump that sprays water onto tangles of rebar, mesh, and steel wire. When the water turns a nice, rusty brown, they pour it off into buckets for storage. The final ingredient will be an acrylic binder, Warner says, “to sequester the rub-off factor. We're coming up with the final recipe now.”
If the idea of earth walls and rust paint gives the impression that this house will be a very large hobbit hole, though, think again. The owner founded a well-known national company headquartered in the Bay area, and he plans to host corporate events on the property. The agenda for this morning's meeting includes discussion of a security system that will allow the owner to assign each visitor an individual clearance profile. During a big party, the system would control, based perhaps on retinal scans, who may enter a particular room and who may not. There's more. The property consists of two 80-acre parcels, one of which the owner will develop as a farm to supply organic produce for his company's headquarters. Redhorse will oversee that project, too, from the many layers of permitting required, to filling a 5-acre lake dug by the previous owner (a bulldozer hobbyist, of all things), to producing the buildings and infrastructure. Which might lead one to ask: If all this is going into one project, what is going into Warner's other 14 active jobs? And who is this guy anyway?
Given his green inclination, it seems fitting that Warner's background includes both construction and the sciences. “I paid my way through school doing construction work,” says Warner, 52, who graduated from the University of California at Berkeley with a degree in conservation and natural resources. But running a construction company was actually Plan B. He was enjoying his first year as a public school biology teacher when California's Proposition 13 effectively eliminated his job. With funding for public education drastically curtailed, “There wasn't going to be much of a future for me in that area,” says Warner, who turned to construction “because that's what I knew.” Redhorse was born soon after. “In 1982 we were starting out with a core group of about five employees, and we were doing small projects, kitchen and bath remodels.” The company's average job size grew quickly, along with its reputation. “All by word of mouth,” Warner says, “just by producing good products and being able to work with clients and work with architects.” As the company expanded, Warner took particular care in choosing people to join his staff. “A lot of them were friends of friends,” he says. “We found the best approach was to find people that we had a commonality with.”
Every successful custom builder can point to a coming-of-age project in his or her company's history, and for Warner, acceptance into the upper echelon came early, with a significant in-town San Francisco residence designed by architect Lewis Butler. A tear-down/infill job on a difficult site for a client in a hurry, the house was complex, Warner says, with “big galleries hanging from the ceiling. It was a threshold piece for us.” Soon after, the company won the contract for a high-profile recreation center project in the city. “It was only like 2,000 square feet,” Warner says, “but it was designed by Jim Ream, who is a noted church designer. It was a gorgeous little jewel box. There was a lot of ceremony about it. That helped us too, because it was a public project and it caught the eye of a lot of people.” The common theme in these two early projects was Warner's willingness to tackle technically challenging, high-visibility work. It is a theme that runs through the company's work to this day.
But there are others. “Probably simultaneous with that,” Warner tosses in, “was one of our first sound studios for a rock band.” A remodeling job for Huey Lewis led to some work for guitarist Joe Satriani, and before long Redhorse had developed a subspecialty in private sound rooms and recording studios. “We did work after that for all of the band members of Metallica. We did work for the Grateful Dead. We're doing some small work for Green Day.” Like much of what defines Redhorse, the music connection is the result of Warner's inclination to say, “That sounds cool; we can do that.”
“I love music, but I don't play music at all,” he says. “I'm just really good at figuring out mechanical issues in terms of what people want.” Across the bay in San Francisco, Warner says, “We're doing the most advanced sound room in the country.” Designed by John Storyk, the architect and acoustical designer responsible for Jimi Hendrix's famed Electric Lady Studios, it may also be the greenest recording studio ever built.
That's another thing about Warner: There always seems to be another thing about him. Here's one more: It was a connection in the music business that led him, by and by, to set up a factory in Alberta, Canada, to produce environmentally friendly structural sheathing panels from wheat straw (see “Straw Man,” below).
But before we can get too far on that subject we pull up at another Redhorse project, this one near Palo Alto, Calif., 100 miles to the south of the Napa house. The site is a narrow ravine that rises steeply from a seasonal streambed. “This is a 10-acre bowl,” Warner says. “The property goes all the way to the ridge tops.” The house, now nearing completion, literally bridges the ravine, a 196-foot, flat-roofed bar whose ends disappear into the opposing hillsides. The building's exterior walls are lined with Corten steel panels, hung with a system of clips that Warner developed, and broad runs of glass that reflect the site's dry grass and green trees. Inside the garage—whose perforated stainless steel door accordions up and out, like an airplane-hangar door—journeyman carpenter Keith Wiley is cutting the aluminum channel that will wrap some interior steel columns. Inside, the building has the spare, quiet air of a contemporary art museum, with an 84-foot wall of floor-to-ceiling glass facing uphill to the rear, stringently simple geometry, and zero trim.