The stately brick and terra-cotta building with vaulting four-story window arches represents a quintessentially New York City phenomenon: the architectural landmark that nobody notices. Built in the 1890s on a fashionable corner in Greenwich Village, it was designed for a long-forgotten retailer who dreamed of giving Macy's a run for its money. Passersby would probably not be surprised if the structure disappeared overnight to be replaced with a modern apartment tower. They would never guess that this venerable edifice is the most energy-efficient building in Manhattan.
Yet the headquarters of the National Audubon Society is that and more. Extensively refurbished last...