You wake up, take a deep breath of scrubbed-clean air, and stroll outside to your terrace, plucking an organic orange from a vegetated wall. You head back inside to the kitchen to make yourself some fresh-squeezed juice, then take the dog down to the park on the 26th floor for a walk. Later you shower, comfortable in the knowledge that a gray water system will thoroughly filter and reuse the water to irrigate those shrubs on 26. You dress and hop the elevator directly down to the neighborhood transit station, where you catch the clean-fuel bus to work.

If those who study high-rise housing are correct, this vision represents the near future for many urban dwellers. According to the Population Reference Bureau, the global population—currently 6.6 billion—will balloon to 9 billion by 2050. To satisfy the world's growing housing needs in a sustainable way, many experts are recommending building up, not out. Whether that approach translates into structures of six or 60 stories, it will certainly result in denser neighborhoods, which generally consume fewer resources than sprawling ones do. “High-rises are green, without any question whatsoever,” says John McIlwain, senior resident fellow for housing at the Urban Land Institute. “Your average high-rise uses less energy than a LEED-certified development in the suburbs.” Most tall residential buildings are located in urban areas, close to public transit and retail. Their inhabitants can commute, shop, and dine out without driving—thus shrinking their carbon footprints.

Pioneering green firms like FXFOWLE Architects, Cook+Fox Architects, and Pelli Clarke Pelli Architects are quickly bringing items like vegetated roofs and gray water treatment closer to the American mainstream. “The technologies necessary to build green high-rises used to cost more because they hadn't reached a level where they were competitive,” says Carol Willis, founder and director of The Skyscraper Museum in New York City and an architecture professor at Columbia University. “Now they're much better tested and more affordable.”

City governments also are doing their part to make green high-rises attractive to developers: Seattle, for example, offers increased height limits to projects registered for at least LEED Silver status. “There's the strategic aspect of green building: the environmental impact, the energy impact, the public health impact. High-rises are very much a part of that strategy,” says John Dalzell, AIA, LEED AP, senior architect with the Boston Redevelopment Authority. “There are also economic advantages. The city becomes far more competitive when we adopt these sustainable strategies, and we attract more business.” He should know: since late 2006, Boston has required buildings exceeding 50,000 square feet to meet basic green standards.

For all their benefits, high-rises aren't everyone's favorite building type. They do tend to cast shadows and block views, and they usually contain high-embodied-energy materials like concrete and steel. But it's hard to dispute the environmental logic of stacking dwellings within a relatively small envelope, rather than spreading them across the land. “There's an inherent efficiency to locating a project within an existing urban fabric,” points out Brendan Owens, vice president of LEED technical development at the U.S. Green Building Council. “You're not creating new roads and power lines. These buildings can be extraordinarily green.”

And ultimately, the price for a life-sustaining natural environment might be a blocked view or two. “In the end we all need to live with each other, for crying out loud,” says Zoltan E. Pali, FAIA, design principal of Studio Pali Fekete architects in Culver City, Calif. “There is no perfect solution. The population is growing.”

But these facts don't stop him and his peers from striving for high-rise designs that unite aesthetic and environmental demands. As long as architects keep this goal in their sights, the possibility of a green and beautiful future is no tall tale.