All Frank and Monika Levinson hoped for when they planned their sleek, contemporary Tiburon home was that it would be beautiful, comfortable, eco-friendly and energy-efficient. Within a year of its completion, however, the house would earn two top construction industry awards and one green building award and rank among the first homes in the Bay Area to earn a GreenPoint rating from the nonprofit Build It Green. This fall, it will be featured in an exhibition at West Coast Green in San Francisco. The house also inspired its architect, Colleen Mahoney, to open Green By Design, an eco-showroom just below her Mill Valley architecture office.
Not bad for a stylish but unpretentious house with big views and inspired by an even bigger dream: to be so energy-efficient it would be “literally off the charts,” Mahoney says. “There won’t be another one quite like it because what the clients wanted was almost impossible to do. It could easily have been a tear-down, but with the Levinsons’ sincere interest in being very green, we kept the majority of the structure, the floor plan and the rooflines, but gave the whole home a face-lift with seismic and energy-efficient upgrades.”
Frank Levinson is an engineer who has been interested in energy conservation since the late 1970s, when he formed Levinson Energies, a fledgling energy conservation company that initially attracted only two customers.
Today, he chairs the green building category of the California Clean Tech Open, a business plan competition; philanthropically works with church congregations here and in his home state of Indiana to reduce home energy consumption; and blogs (smallworldgroup.com) about his own home’s energy-conservation progress.
Naturally, he has a philosophical interest in the latter. “I’ve always felt we have a responsibility as people of the world to be better stewards,” he says. “This was my chance to see if we could build (with) a carbon-neutral footprint.”
The two-story, three-bedroom home on two private acres is bright and airy. An attached two-bedroom apartment has its own kitchen and living space for overnight guests, but a concealed monitor and white board lets it double as Levinson’s conference room.
In the main house, Mahoney removed a wall so the kitchen would share the San Francisco bay and skyline views with the living and dining areas. A curved glass staircase in the foyer and glass railings outside further capitalize on the views. “There are ferryboats going back and forth to Angel Island, sailboats and tankers crisscrossing the bay and fog rolling in and out right outside their windows,” Mahoney says. “It’s living art. We didn’t want the architecture to compete with it.”
She collaborated with the couple in choosing green materials such as Forest Stewardship Council–certified maple wood for interior floors, doors and cabinetry and the exterior cedar siding; CaesarStone and Zodiaq for countertops; no-VOC paints and finishes; energy-efficient LED lighting and Fleetwood doors and windows; recycled stainless steel sinks in the kitchens and recycled Oceanside mosaic tiles in selected bathrooms.
She also helped them with non-green choices, such as the granite countertops in the main kitchen. “Frank and Monika made every decision to reduce their carbon footprint, but there will always be unique places where homeowners have to weigh aesthetic choices and ultimately do what makes them happy,” she says. “Granite is durable and beautiful—they truly loved it—and the kitchen is a centerpiece of the house.”
Another collaboration was the clever storage solution for the family’s collection of 1,500 books. Instead of predictable bookshelves in the media room, Mahoney’s team came up with four pull-out stacks concealed within a graceful wall that mirrors the curves of the nearby glass staircase. “That’s just one of the many ‘wows’ in this house,” Mahoney says.
All systems, all efficient
The home is highly insulated for maximum energy savings; there’s soy-based foam in the roof and exterior walls and UltraTouch recycled denim insulation in the interior walls. To make it even tighter, the home’s underside is also insulated with foam sealant and fiberglass batts.
Two photovoltaic systems provide power for everything from house to hot tub, while one solar hot water system heats the home and another warms the pool. “We’ve cut our gas use by 90 percent,” Levinson says. “I’ve replaced the gas furnaces with electric heat pumps, but my wife loves cooking with gas, so we still use gas [in the stove and oven]. On the other hand, we produce more electrical energy than we use, so the house is pretty close to being a net-zero-use house.”
One of the “impossible” aims of this project was to reduce the phantom energy that appliances use simply by being plugged in or in standby mode. The Levinsons cut energy use 70 percent by configuring appliances and electronic devices to turn off automatically when not in use.
Consumption of gas, electricity and water is easily monitored with a real-time Agilewaves home resource monitor, which “shines a light on where you can make changes to reduce your overall carbon footprint,” Mahoney says. Without it, Levinson wouldn’t have noticed that one of his solar panels was defective, losing 25 percent of its output.
Buttons on an in-home energy dashboard control the television, lights, the window shades, the HVAC systems and the security alarm. It was designed for simplicity. “I wanted my grandmother to be able to use it and not be confused,” Levinson says.
Outside, in a landscape designed by Suzman & Cole Design Associates to be subordinate to the view, drought- and deer-resistant plants, many aromatic, hug a steep terrain made accessible by a stone staircase. The garden is irrigated by a sophisticated rainwater collection system of oversize gutters, twin 7,500-gallon cisterns and a satellite-controlled weather-monitoring station.
Even though Levinson figures the house produces enough power to plug in his future hybrid car, he’s not sure the project is finished. “I’ve learned a lot from both the house and the apartment,” he says. “If we took it further, we could probably save another 5 to 10 percent.”
Architect/Interior Design: Mahoney Architects & Interiors
General Contractor: Larwood Construction
Structural Engineer: Weir Andrewson
Landscape Architect: Suzman & Cole Design Associates
Lighting Design: Anna Kondolf & Associates
Home Controls: SoundVision
Photovoltaics: Sun First!