Weird Restrooms. That sign, on Highway 101—“POP 187”—may be enough to make a driver brake, out of curiosity or necessity. But the real attraction here, the one that has drawn more than 300,000 people to this isolated California town since 1996 is a twelve-acre oasis called the Real Goods Solar Living Center. Part retail store, part learning facility, and part demonstration project for the principles of sustainable living, the Solar Living Center is a futuristic space where people can relax, shop, learn about renewable-energy projects, and—if they really want to—gaze upon waterless urinals and bathroom walls tiled with toilet-tank covers.

Founded in 1978 by John Schaeffer, an early-1970s alumnus of both the University of California at Berkeley and a hippie commune, Real Goods began as a small retail store in Willits, California. Its original mission: to promote the use of solar energy as an alternative to fossil fuels. Today Schaeffer, 49, presides as CEO of Real Goods Trading Corp., a $17 million retailer of renewable-energy products, with outlets in Berkeley, California, in Eugene, Oregon, and in Hopland, California. Most of the company’s ­business comes through mail order:

Real Goods sends out more than seven million catalogs annually. But if you want to get the real goods on Real Goods, you have to visit the Real Goods Solar Living Center.

An oft-told piece of Real Goods lore describes a woman who walked into the Solar Living Center one summer and angrily demanded to see the hidden air conditioner. She was politely informed that the building stays cool because of how it was built. Says Jeff Oldham, 46, project manager for the Solar Living Center and lead technician at Real Goods: “People can’t believe that it really works until they walk in the door. Even when it’s 110° outside, it will be a comfortable 75 to 80° inside the store.”

What’s the secret? More than 600 bales of straw, each one 23 inches thick. The bales are stacked like bricks to form the core of each wall. Metal pins, chicken wire, and wooden frames help hold the bales together. A one-inch layer of gunite (a fireproof cement) and a three- to four-inch layer of PISE (which stands for “pneumatically impacted stabilized earth”) surrounds each core.

According to Sim Van der Ryn, the architectural mastermind behind the Solar Living Center, the Real Goods project exemplifies what he calls ­“second-generation ecological design.” “People still tend to imagine that solar buildings have to be mechanistic and unattractive,” he says. “Nothing could be further from the truth. In fact, most of the technology here isn’t new. What is unique and exciting about the Solar Living Center is the integration of that technology with an overall vision and with the environment.”