New York Times: The US federal government has just finished building the nation’s largest zero-energy office building—the Research Support Facility on the Department of Energy’s National Renewable Energy Laboratory campus in Golden, Colorado. To qualify as zero-energy, a building must create as much energy as it uses over the course of a year. Besides solar panels and a low-energy radiant heating and cooling system, the building has other energy-saving features. Windows can be opened to provide ventilation, and the walls consist of a layer of insulation sandwiched between two concrete layers, which will absorb heat during the day to keep the interior cool, and then release the heat at night.
