Why aren’t our roofs white? Should we ban sprawl? And other questions asked by green urbanist and architect Steffen Lehmann
Steffen Lehmann gets animated about a lot of things. During a recent interview, the director of UNLV’s School of Architecture talks enthusiastically about his early career in his native Germany, running his own office in East Berlin months after the wall came down; his search for knowledge in Japan that landed him a coveted job working for Pritzker Architecture Prize-winner Arata Isozaki; his life as an academic nomad, which has taken him to 40 countries in the last 25 years; and Mawson, the 13-year-old cocker spaniel that accompanied Lehmann from Australia a year ago — and now has a cozy bed in his office.
But what excites Lehmann the most is a 900-page doorstop of a textbook titled The Principles of Green Urbanism. He wrote it a decade ago.
He slides it across his desk; it’s as thick as the two reams of paper he uses as a monitor stand. The book has been used on countless college campuses, translated into Chinese, and is still in print. The title sounds optimistic, even utopian. But the book endures, Lehmann says, because the ideas inside are anything but. He refused to look at a green future with rose-colored glasses, and avoided laying out anything approaching a “green utopian dream.”
“I am representing a generation that thought that, truly, utopia was dead and we had to engage with the opportunities of reality,” Lehmann says. “It was the first comprehensive ‘pulse check’ on what architecture could do in terms of the environmental crisis.”
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It can do a lot — a little at a time. Green urbanism is about making communities that are livable for humans and sustainable for the earth. In his book, Lehmann lays out different models for sustainable urban growth, with an emphasis on energy-efficient, net-zero carbon strategies intended to “futureproof” the post-industrial city. And with the zeal of an evangelist, Lehmann preaches the book’s lessons today in a community better known for excess than environmental awareness. “People who know me will tell you that I am like a machine,” he says. “I do basically nothing else except spread the word on these topics.”
But what relevance does green urbanism have to Las Vegas — a sprawling, postwar pastiche of suburbs whose economic engine is consumptive, escapist tourism? Actually, a lot. Best of all, you don’t have to read a 900-page tome to learn what it is. Distilled from his book, Lehmann’s ideas range from the modest and practical to, well, a little utopian. Some we’ve all heard before. But his post as head of the UNLV School of Architecture means he’s positioned to influence a new generation of architects, and encourage them to build these ideas into their future practice. In a wide-ranging talk recently, he discusses ideas such as:
• Reducing urban heat. The use of reflective and white roof materials can reduce the dangerous “urban heat island” effect and keep roofs cooler. The worst scenario? A black-colored roof, as it requires much more energy for cooling during summer.
• Growing in, not out. Las Vegas, Lehmann says, would do well establish a strict growth boundary to limit the increasing footprint of the city, and help to stop further sprawl into the desert landscape. Las Vegas should develop toward its center, not outward. A large number of vacant, low-density sites and rundown parts in the city should be tackled first, and development limited to already built-up areas.
• Gentle densification. Las Vegas was in the grip of mid-rise and high-rise fever in the early aughts, but Lehmann proposes we scale our ambitions back. “There are real opportunities to increase urban densities through buildings with three-to-five stories. We need multistory buildings, not high-rises, that put four units on a site where only one unit currently sits. This will help with the housing shortage while making Las Vegas more compact, mixed-use and walkable.”
• Live where you work, work where you live. Inner-city apartment living is more sustainable than large suburban houses far away from workplaces, and we should encourage it. Bringing living and working closer together again is a good strategy, reducing the need to constantly commute. In this model, apartments are arranged above commercial spaces, which are on the ground floor, allowing for higher density, reducing apartment sizes into a 400- to 500-square-foot “efficiency unit.” This opens up all street frontages to natural airflow and daylighting, and cuts back on the need for on-site parking. When a neighborhood offers good walkability and public transit options, on-site parking can be radically reduced.
Outside the halls of academia, Lehmann pushes his students to explore how other cities are striving for sustainability through architecture. Noting a high percentage of Spanish-speaking students at UNLV, Lehmann created exchange programs with institutions in Spain and Latin America. The students study for four weeks in other hot-weather cities that are also on the front lines of coping with climate change. They return with fresh perspectives and valuable connections.
“This experience is as important as anything that happens in the classroom,” Lehmann says. “The young people we educate here will be the decision makers of the future, and the more perspective they have, the better decisions they will make.”
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