It seems the first little pig, looking for an affordable yet solid home, may not have been too far off base in choosing straw as his primary construction material.
The Shorebird Nature Center in the Berkeley Marina, with a handful of local volunteers, raised the straw bale walls of a new 860-square-foot facility earlier this month. The new facility, which will adjoin with the current building where visitors are taught about birds and the bay, includes a 450 square-foot outdoor classroom, office space, a visitor’s center and additional teaching space.
The addition is said to be the Bay Area’s first public building made of straw bales.
Although straw bale construction has emerged as a trend only recently, the concept has been around for nearly a century. At the beginning of the 20th century, homesteaders in the Nebraska “Sandhills” turned to bale hay construction due to a shortage of trees for lumber. The oldest existing bale building was built in 1903 in northwestern Nebraska. It still withstands Nebraska’s wild temperature swings and blizzard-force winds.
In Berkeley, the primary building material for the Shorebird Nature Center is straw bales made of rice. The bales are also commonly made from wheat, oats, barley, rye and flax.
Following this month’s construction of the walls, the bottom straw bales will be enclosed in a water-resistant sheath and steel rods will be pounded through the bales for added stabilization. Wire mesh and stucco will also be used to further secure the structure. Completion of the structure is expected late this fall.
The benefits of using straw bales – which unlike wood are renewable annually – in the construction of homes and commercial buildings are numerous.
“There are a myriad of environmental reasons [for using straw bale construction],” said Greg Van Mechelen, a contractor at the nature center with Van Mechelen Architects in Berkeley.
Straw bale buildings make use of material that would otherwise go unused – the stalks remaining after the harvest of grain. Normally that refuse is burned, creating pollution.
One million tons of straw were burned each year in the mid-1990s in California, according to Dietmar Lorenz, an architect for Dan Smith Associates of Berkeley who is also helping with the Shorebird Nature Center project. While that refuse could have been used to create nearly 100,000 new homes, instead it generated more carbon dioxide emissions than all of California’s power plants combined, Smith said.
“If you go up to Sacramento in October, you will see a haze from the burning of that straw,” Van Mechelen added.
Straw bale buildings have another long-term benefit. The straw is more solid as an insulator than traditional types, so it saves money in utilities. Straw insulation is more earthquake resistant and acoustically sound. And, the building will hold up better during a fire.
“Six years ago people had no idea [about straw bale homes],” he said. “Now, people have an idea and are requesting more environmental-friendly buildings.”
Lorenz, whose firm has completed more than 40 straw bale projects, has seen an upswing in people requesting “green” homes.
“It’s really gaining momentum very quickly,” Lorenz said. “Every year there is increased interest.”
Although using straw bales can increase building costs 10 percent to 15 percent, Lorenz and Van Mechelen agreed that consumers quickly make up the expense through other benefits.
“In the end you get a much more substantial house in terms of quality, longevity and operating costs,” Lorenz said.
Straw bale buildings are also more conducive to the “do-it-yourselfer.” “If you do some of the construction yourself, you can save money,” Van Mechelen said.
The center is being constructed with grants from Lawrence Berkeley National Laboratory, Department of Energy, West Berkeley Foundation, The Strong Foundation, Builder’s Bookstore, the city of Berkeley and individual contributions. In addition, the California Integrated Waste Management Board and the Alameda County Waste Management and Recycling Board are also major funders of the project.
Other environmental features of the new building include passive solar design, integrated photovoltaics, hot water solar panels for radiant heating system, natural linoleum floors, recycled and sustainability harvested wood framing, cabinetry from wheat straw particleboard and countertops made from recycled glass.
Construction of the Shorebird Nature Center addition is due to be completed in November. It will be open to the public six days a week for presentations, workshops and open houses.