More than just a rebuild, this Marin home was the first in the country to use a new bamboo framing system.
LESLIE AND JACQUES LESLIE HAD A SIMPLE goal when they decided to renovate their home in the hills of Mill Valley. “We wanted the greenest house we could build,” Leslie says.
Both are committed environmentalists. Jacques, an award-winning journalist who covered the Vietnam War for the Los Angeles Times, now writes about water and energy issues. Leslie, an artist who creates works based on the Buddhist loving-kindness prayer, has long been involved with nonprofits like International Rivers, for which she sits on the board.
The couple wanted a home that reflected their passions. The result exceeded even their greatest expectations: a stunning modern home that stands at the intersection of the environment and art, as eco-friendly as it is serene and visually arresting.
It’s also a healthy home, which distinguishes it from the Southwestern-style house that stood on the property before. The Leslies loved that home, which they bought in 1983. It was cozy and had arches and they raised their three (now grown) children there. But the house was dark and cold, and Leslie and the kids suffered from asthma, bronchitis and sinus infections while living in it. It was only later that they learned the walls were filled with black mold.
The Leslies had wanted to renovate the home ever since becoming empty nesters. They took the plunge in 2012 but the architect they hired proved to be such a disaster that they filed a lawsuit against him (and won). They considered moving but couldn’t find anything they liked better. Finally, they decided to stay and tear the house down. This time, they struck gold with an architect: they hired Daniel Weaver, of Sausalito’s 361 Architecture, whose specialty is sustainable and net-zero energy homes.
Weaver sat down with the Leslies and asked for their wish list. “They told me they wanted a home with a lot of light that took advantage of the site,” says Weaver. “But in terms of the style, they were a fairly open book. They didn’t come to me and say, ‘We want a warm modern house’ at all.” Weaver spent time surveying the half-acre property, which had a house closer to the road and a yard that sloped down to a level area with a pool and dilapidated tennis court below. He observed Leslie as she moved a chaise lounge around the yard, trying to find the sun. He realized the house was in the wrong place.
He then suggested that the Leslies build their new home where the tennis court stood, in the flattest part of the yard. He also thought the house should face west, to capture the afternoon sun. A pool was important, as Jacques is a daily long-distance swimmer, so Weaver envisioned a sleek, 25-yard lap pool and deck in the center, with the buildings — including the home and the writer’s and artist’s studio — wrapping around it. “I wanted to have the structures kind of cradle that center area and then have the other side, the negative space, be the garden that would eventually fill in around it,” Weaver says.
In order to make the home as eco-friendly as possible, Weaver encouraged the Leslies to try a groundbreaking prefabricated bamboo panel technology from a Windsor, California, startup called BamCore (see sidebar). The bamboo paneling would eliminate the need for wood stud framing — a common path for heat to enter and escape a home. The Leslies and their contractor, David Hill of Spellbound Construction, were game to try it, especially because the new technology would allow them to put more insulation in the walls and increase energy efficiency. They ordered the prefabricated panels, making theirs the first custombuilt house in the country to use the bamboo framing system.
Weaver also incorporated other eco-friendly features into the design. He installed solar panels atop the building that houses Jacques’ writing and Leslie’s art studios, and the panels now generate enough energy to heat everything but the pool. Because of the way the house is designed — with a west-facing orientation, soaring windows and glass doors, and a tight thermal envelope, due to the bamboo paneling — the Leslies draw very little energy, keeping the radiant heat at a constant 67 degrees. In the summer, they heat the saltwater pool with a solar cover.
To conserve water, the Leslies installed a gray water system, which funnels water from sinks, showers and the dishwasher to the salvia, blue fescue, and roses in the mostly drought-tolerant garden (designed by Roth/La Motte Landscape Architects). And behind the house, the Leslies have built a bioswale, which collects runoff rainwater in the ground rather than letting it flow into the stream behind their property. The idea was to help increase groundwater supply, a resource that is being depleted all over the globe. The bioswale area is beautiful, teeming now with horsetails and native grasses.
Weaver integrated all these eco-features into the home in a way that is seamless and nearly invisible. The structure’s clean and modern lines, as well as its surprising warmth, are what stand out most. It’s little surprise that Weaver drew upon traditional Japanese design in his drafts, and in particular the work of Tadao Ando, a contemporary architect who uses empty space to highlight the beauty of simplicity. “I wanted to execute the details of the house in a very simple way,” Weaver says, “but you know what Vincent van Gogh said: ‘How difficult it is to be simple!’ ”
For proof, one need only look at the Leslies’ roof. A butterfly roof — which dips in the center and ascends towards the sky at its edges — it was originally built to collect rainwater (an idea that the Leslies abandoned after discovering how expensive the system would be). Now, it lends a soaring appearance to the exterior and brings more light into the home. On the inside, it’s all drama; every ceiling in the home is angled.
Despite its proliferation of right angles and lack of halls, the house has a personable feel. Weaver achieved this effect by including “clouds” — floating planes that hang from the ceiling — to separate spaces in the loft-like great room. “They remind me of the philosophy of art historian Vincent Scully, who was a popular professor when I was at Yale,” Jacques says. “He always talked about how you needed a human dimension. These clouds provide a human dimension.”
Weaver separated the space between the living room and dining area with a low-slung built-in bookcase, providing storage for the couple’s many books. And the home has ample wall space for their art collection, which includes works by Robert Mapplethorpe, Henri Cartier-Bresson and Roy Lichtenstein.
The Leslies made their own contributions to the project, as well. Both of them love blue, and indigo in particular, so when it came time to choose a color for the exterior of the studio — as well as interior doors and kitchen cabinets — Leslie dug in, putting her artistic skills to work. She and their painter spent three days mixing paints until they reached a blend of five colors that matched that of traditional Japanese-style indigo dye. It’s one of the only colors in the home, along with gray. Having so few colors had its desired effect: “I really felt it made everything calmer,” says Leslie.
Like everything else in the home, the paint color required effort, and the result reflects only simplicity and beauty.
BAMBOO PANELING TECHNOLOGY
The Leslies’ home was built with a groundbreaking, code-compliant bamboo paneling system created by BamCore, a startup in Windsor, California.
What’s so innovative about this new technology? For years, builders have sought an alternative to wood stud framing, which is time-consuming to erect, reduces thermal efficiency and interrupts the space between walls that could be filled with insulation. Ten years ago, BamCore founder William McDonald was mulling over this dilemma with fellow builders when they hit upon the solution: timber bamboo.
Timber bamboo is an exceptionally strong and sustainable plant. An average bamboo culm grows 60 to 120 feet in a year, and, according to BamCore CEO Hal Hinkle, an acre of the plant yields approximately 10 times as much building material as an acre of wood.
BamCore’s breakthrough was to figure out how to flatten the round culms with a process that uses no heat, chemicals or water and bind them together with formaldehyde-free glue. The result: structural panels so strong that the company had to add a Douglas fir veneer just so builders could drive nails into it.
In construction, two parallel bamboo panels are held in place by top and bottom steel tracks, leaving a hollow cavity in between. The cavity can then be filled entirely with insulation, creating a much tighter thermal barrier around the house than traditional wood-stud framing.
One word of caution: if you’re thinking of using this technology in your next home, don’t hold your breath. BamCore is currently cutting its prefab panels at a prototype factory and only has the capacity to build a few homes per year. Until it moves to a mass-manufacturing plant, you can expect to join a waiting list.