Two weeks after Tredje Natur won the design competition, a 500-year flood inundated Copenhagen, making water management an even higher priority for the city. In the U.S., more erratic climate patterns of severe rainstorms with periods of drought are motivating designers to expand existing sustainable stormwater-management practices. And on-site conservation measures can provide a hedge against periods of water scarcity.

For the Germantown Friends School's new science building in Philadelphia (completed in 2010), SMP architects designed a multifaceted, interactive water-management system. The school has two levels of green roofs; one is accessible for demonstrations. Stormwater drains into two 4,800-gallon cisterns that provide graywater for the toilets in the building. The cisterns overflow into rain gardens clustered around the courtyard, which slows the flow further before it's dumped into the city's stormwater system.

Resilience and Green Building

Some leaders of the green-building movement are including resilience as a key ingredient in sustainable buildings. Alex Wilson, founder of BuildingGreen, recently formed the Resilient Design Institute, a nonprofit organization and think tank that promotes practical solutions in resilient design.

In 2005, after Hurricane Katrina, Wilson coined the term “passive survivability” (he now favors “resilience”) to refer to a building's ability to maintain critical functions through extreme events.

“Dramatically improving energy performance of buildings should be a high priority for resilient design,” Wilson says. He points out that in the aftermath of natural disasters, extended power outages with the loss of heating and cooling are one of the most persistent problems. “Even here in Vermont, we can make homes that never get below 50 degrees in the winter—just by virtue of a high-performance envelope and passive solar design,” he adds.

On-site power generation such as solar-photovoltaic systems can also help buildings survive extreme events and act as a backup when the grid fails. However, as some New Yorkers discovered after Sandy, most grid-connected PV systems are useless when the grid goes down. To make PV systems viable during power outages, homeowners have to install special inverters and a battery-storage system.

The U.S. Green Building Council has long advocated for climate-change mitigation, addressing the issue through the reduction of greenhouse-gas emissions. In 2011 the organization joined the University of Michigan to produce a study called Green Building and Climate Resilience.