BERKELEY — Most Californians have come to accept the floods, fires, earthquakes, and mudslides that regularly ravage so many parts of the state. Eugene Tsui has decided to do something about them--or at least try to protect his family from the worst of their consequences--by examining how other animals adapt to their environment.
Tsui, a maverick architect working out of Emeryville in the Bay Area, is currently overseeing construction of a Berkeley home for his parents: a $250,000 structure that he says is quake-proof, flood-proof, fireproof and termite-proof.
The 1,900-square-foot, three-level dwelling includes four bedrooms, three bathrooms, a kitchen, a dining/living area, an outdoor patio and a partially underground garage. It is, to put it politely, a little odd-looking. But then, what would you expect from a building that's modeled after a microscopic animal called a tardigrade that lives in water or damp moss.
"To make the house as indestructible as possible, we looked at what nature could teach us about design," says Tsui. "The tardigrade can withstand extreme living conditions and survive sudden environmental stresses. By observing the animal, we understood that its durability depended on its shape, so we tried to translate its form into the building."
Tsui calls his special brand of design "evolutionary architecture." To date, he has built 10 structures that borrow design elements from nature. His goal is to create buildings that are "organic" rather than "static," and thus can respond to the natural stimuli that characterize a particular site.
The exterior of the Berkeley house (which Tsui has dubbed Ojo del Sol, which means Sun's Eye), is distinguished by a continuous wall in the form of an ellipse, "one of the strongest structural shapes known to exist," says Tsui. All the home's walls are connected and load-bearing, so any structural stress during an earthquake would be evenly distributed.
A conventional, box-shaped house, by contrast, concentrates stresses in corners and joints, making it vulnerable to collapse.
"Nature doesn't make boxes," Tsui points out. "Our movements and our bodies are not made up of straight lines and angles and flat planes, but most of our architecture is. I feel that soft, curving structures offer a kind of primal relationship with living things that's rooted in our emotions, our psychology, and our physiology."
Structural engineers are not generally given to discourse on primal relationships, but they agree that the shape should give Tsui's house greater resistance to earthquakes.
"This sort of smoother, elliptical plan provides a stiffer system that can really help distribute seismic forces around the structure," said Gregory Fenves, a professor of structural engineering at UC Berkeley. "It's a very creative architectural solution."
And the voluptuous curves offer fire protection as well. Wind-tunnel tests conducted at UC Berkeley after the 1992 Oakland firestorm showed that the flat planes of typical houses can harbor air pockets that suck spreading flames toward the walls. Curves, on the other hand, foil this vacuum effect and encourage the flames to flow around them, just as air currents stream around an airplane wing in flight. The house includes more conventional protection too: a ring of eight water jets that will immerse the exterior of the house in the event of fire.
The foundation and first floor of the home consist of building blocks made from recycled Styrofoam and cement, reinforced with steel. Known as Ener-Grid blocks, they're fire-resistant, waterproof and termite-proof, and create a reinforced lattice design that resembles the skeleton of the cholla cactus--another hearty organism observed by Tsui.
Richard Meier, a professor of architecture and planning at Berkeley, pointed out other advantages of the Ener-Grid foundation: It's lighter and held together by steel cables, and is sunk four feet into the ground. That should provide protection on a landfill site that is prone to "liquefaction"--turning into something resembling jelly--in an earthquake.
Ojo del Sol offers energy-efficiency as well as protection from natural disasters. The huge oculus window warms floor surfaces inside the house by day, and at night, that collected heat radiates into the home's interior. Black, air-filled pipes embedded in the south side of the building concentrate solar energy during the day, and then heat the home at night.
Tsui's study of the bone and capillary systems of two dinosaurs--stegosaurus and dimetrodon--inspired this subsurface solar heating system: Both reptiles sported plate structures surrounded by many capillaries.
"Nature has had millions of years to work out its forms," noted Meier. "When nature chooses a form, the choice is extremely conservative and extremely efficient."