Earth Day Pictures: 10 Of World's Greenest Buildings

Eco-friendly buildings can be both affordable and beautiful, say the jurors of an annual architecture award.

They have super-insulated walls, solar panels, green roofs, and veranda-like canopies. Plus, they look Dwell-like cool.

On Earth Day, ten modern buildings were crowned winners of the American Institute of Architects’ annual sustainable design competition. They showcase attractive ways to reuse construction materials, save water and energy, and improve indoor air quality.

The Top Ten Green projects include research labs, office buildings, and a university dorm. In Oakland, California, a pasta factory was remade into an affordable housing development. In San Antonio, Texas, a military medical hospital uses natural lighting as part of the healing process and in Sonoma, California, a living community for autistic adults includes a community center, therapy pools, and urban farm.

Like several winners, Seattle’s Bullitt Center produces as much energy as it uses via rooftop solar panels, but its location earned particular applause. “If a net-zero office building can be built in Seattle, one of America’s cloudiest cities, then one can be built anywhere in the nation,” say the jurors on AIA’s Committee on the Environment. (Read an interview with Earth Day founder Denis Hayes about the Bullitt Center.)

The AIA also gave an award to a prior winner that has proved its worth. The U.S. Army Corps of Engineers' Seattle headquarters, built on a former toxic brownfield, is now an exemplar of energy efficiency.  After one year of operation, testing showed it used 61 percent less energy than the U.S. average for similar buildings.

The story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

On Twitter: Follow Wendy Koch and get more environment and energy coverage at NatGeoGreen.