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Prefab Green

   When architect Michelle Kaufmann and her husband put together their wish list and went house hunting in the Bay Area, they discovered they could only afford a “teardown” house, but wouldn’t have any money left to build the well-designed green home they envisioned.
   Determined to create an efficient, green dwelling, the couple purchased a narrow lot in Marin County and quickly designed a three-bedroom, 1,560-square-foot home, nicknamed “the Glidehouse” for its sliding glass doors, sliding wood panels and sliding wood sunshades.
   Friends and colleagues of the couple wanted green houses, too. It provided the genesis for Kaufmann’s quest to provide mass-produced prefab homes. She found a factory willing to take a chance, and the first identical Glidehouse was built in four months versus the 14 months it took to build on site and came in at a cost of 15 percent less than the original.
   While Kaufmann was developing her prefab green houses, Sunset Magazine was looking for a draw to the company’s annual spring lifestyle weekend in Menlo Park. The editors chose the Glidehouse to be their featured attraction and ordered one for the site.
   The Glidehouse opened to record crowds—the lines stretched out of sight. In two days, 25,000 people had seen the house, some more than once. Witnessing the shocking demand for affordable, contemporary, green housing, Kaufmann became even more determined to make prefab green housing an attainable reality. She is part of a new generation of architects who are taking the old ideas of prefabrication and accommodating it to climates and lifestyles, along with respecting the environment. Her journey led to the creation of Prefab Green, published earlier this year by Gibbs Smith and co-authored with Catherine Remick. It’s guide to blending sustainable home layouts, eco-friendly materials and low-energy options in a modular, prepackaged form.

What is Prefab Green?
   Prefabricated housing has been the term to describe any house that is built partially offsite. It’s any structure that is manufactured in a standard size and can be shipped and assembled elsewhere. These can be kit homes, panelized homes, manufactured housing (think mobile homes) or modular homes.
   Kaufmann chose modular technology because most of the house is factory built, but it has all of the characteristics of traditional stick-built homes and must meet all code requirements.
   “Automation and technology bring good design to the masses,” Kaufmann says. Building from the ground up is “like asking your car to be built in your driveway for you.”
   She was able to prepackage green solutions for her clients, combining different sustainable systems and materials into one bundle. Features such as solar panels, water catchment and greywater systems allow for more sustainability.
   In addition, building in a factory nearly eliminates scheduling problems due to bad weather or delays with the builder. The same specialized construction team builds each of the modules, and materials are stored in a controlled environment, eliminating damage from warping and mold.
   Fifty to 70 percent of normal construction waste can be eliminated in this type of structure. Nearly a third of the nation’s landfills are filled with construction waste. The amount of materials used is less due to precision cutting, and scraps can be stored for reuse or recycling. If that’s not enough, there is a significant amount of gas saved by contractors driving to and from work. While scaling back on her large-scale expansion plan due to the struggling economy, Kaufmann says her niche is garnering more calls than ever before from builders and developers. “They want less risk and low inventory along with better inventory control,” she says. “They also need marketability and differentiation in the market.”
   Kaufmann feels strongly that this new way of building green is here to stay. “My hope is that five years from now we won’t even be talking about it,” she says.

The Five EcoPrinciples
   Due to the confusing array of green and sustainable products flooding the market, Kaufmann developed a set of guidelines she calls “EcoPrinciples” to give consumers a way of understanding and determining ways to go green.
   “Opinions vary on the best ways to create a sustainable environment, and in the end you need to decide what works best for your life,” Kaufmann says. “It’s getting increasingly foggy, and it’s not easy to find the best solution and how to get the best bang for your buck. Educating people about going green is very important to me.”
   The EcoPrinciples aim is to help consumers decide what the best options for their homes are. Here are some principles to consider when looking to “green” your home.

Smart Design
   According to Kaufmann, the average American living space tripled from 290 square feet per person to 900 square feet per person between 1950 and 2004. However, people feel more comfortable in properly scaled, cozy rooms rather than large ones. Think about how people gravitate to the kitchen at parties. It’s more than just the food. Building less and maximizing living space through good design is the first step. Exterior space should be as well-designed as the interior of the home. Glass windows and walls can expand interior space to include the natural environment. On the inside, try to have as much furniture as possible serve double functions: think sofa beds, wall-mounted bookshelves and beds and stools with storage spaces. By designing roof decks, gardens and green roofs, every space of the home can be used. Glass walls and skylights reduce the need for electricity and can heat and cool the home as naturally as possible.

   Use renewable and sustainably harvested materials like bamboo for flooring and wheatboard and particleboard for cabinets. Recycled materials can be used throughout the house. Long-lasting and low-maintenance materials can save a lot of maintenance in the future. For example, a roof made of weathering steel can eliminate the need to ever reroof your home.

Energy Efficiency
   According to Kaufmann, buildings account for 40 percent of total energy use, 70 percent of total electricity consumption and 38 percent of total carbon dioxide emissions. A green home should have a tight seal between the foundation, roof, walls, doors and windows. Installing efficient light bulbs like light-emitting diodes (LEDS) and compact fluorescent lamps (CFLs) is another way of reducing energy. Look for appliances with the Energy Star logo, which have met energy efficient guidelines set by the Environmental Protection Agency and the U.S. Department of Energy. There are also a wide range of efficient heating and cooling systems. Consider going retro and use ceiling fans instead of air conditioning. “Cool roofs” keep heat from entering the building. Installing solar panels have a large initial investment, but the average time for recouping your initial investment is five to 10 years. A solar thermal water heater uses the sun’s energy to heat the water for your home.

Water Conservation
   Reduce the amount of water used by installing low-flow toilets and low-flow showerheads. Xeriscape your yard. Lawn watering uses about eight gallons of water per minute. Xeriscaping is using drought-tolerant plants that don’t require a lot of fertilizer or extra water. Try to use indigenous species. Reuse water by collecting rainwater runoff from your roof to use off-season for your xeriscaping. By planning site-water management you can reduce damage to your property and pollution of the local water sources caused by storm-water runoff. Permeable materials for walkways and driveways like pervious concrete, decomposed granite and grasscrete, a combination concrete-grass system, can help to absorb rainwater.

Healthy Environment
   The insides of our homes are filled with toxic chemicals that pollute the air we breathe. Latex wall paint is full of carcinogens linked to asthma in children. Many construction materials use formaldehyde, a powerful toxin. Wheat board and FSC-certified wood materials are formaldehyde-free. HEPA filters are used in hospitals and nuclear labs and can remove 99.97 percent of small airborne particles. Kaufmann recommends a filter for every home. She also uses spray-in foam insulation because it is 37 times more effective than fiberglass batts or boards. It helps to prevent mold because it expands to fit the framing cavities and controls moisture. Forget about carpeting unless you use washable carpet tiles. Recycled material tiles or FSC-certified woods are the cleaner choice.

Green Software
   New software programs are designed to compare energy efficiencies in homes. Kaufmann uses EnergyPlus, which can model and compare heating, cooling, lighting, ventilation and water loads. It allows her to study strategies and effectiveness in local conditions and then simulate different systems to ensure energy efficiency.

Green Remodeling
   Some surprising statistics make the Obama stimulus provision to hire people to make our homes more energy-efficient seem wise. The book points out that “if every home in the U.S. was insulated, it would put an end to our country’s dependence on Middle Eastern oil. An Energy Star-qualified refrigerator in every U.S. home would shut down 10 aging power plants.”

   Dreaming Green: Eco-Fabulous Homes Designed to Inspire by Lisa Sharkey and Paul Gleicher is a photography-filled book of 17 stunning green homes meant to inspire us all to do something green in our habitat. It was published late last year by Clarkson Potter.
   Parents of three growing children, the authors, an architect and a media professional, wanted to protect their family from environmental toxins. They decided to go completely green and spent countless hours learning what that really means. The result was the transformation of a Manhattan Upper West Side townhouse built in 1885 that had been converted from four rental apartments into a showcase of green technology, finishes and furnishings.
   Their search for other earth-friendly homeowners unveiled green pioneers who used the coolest eco-friendly alternatives with dazzling style across the country. Homes featured in the book range from an English Tudor to a farmhouse to a waterfront mansion.
   Green doesn’t have to mean more expensive. A useful resource section gives a wide range of vendors who supply everything green from roofs to foundations.

Smart Home at the Museum of Science and Industry
   The Smart Home designed by Michelle Kaufmann Designs is on display behind the Museum of Science and Industry. WIRED Magazine has equipped the house with new and unique home technologies, and the home’s landscape shows techniques for urban gardening, including vertical gardens and EarthBox planting.
   The full scale, three-story modular green home was on exhibit in 2008 and drew more than 100,000 visitors. Due to its popularity, the Smart Home is open again this year. Tickets are available through the museum.

Published: April 04, 2009
Issue: 2009 Spring Green Issue