Source: news.nationalgeographic.com
Published: January 20, 2015
NOTE: This article requires a National Geographic account to view.
Three miles northeast of the White House, now topped with solar panels, six modest new row houses are expected to deliver world-class savings in energy.
The reason’s simple: They’re so well sealed and insulated that they perform just like a coffee thermos. No furnaces are needed, because they’re projected to use up to 90 percent less energy than a typical house.
Built partly by volunteers, these low-budget Habitat for Humanity homes—now nearing completion—don’t look like anything special. They have basic brick facades like others in their gentrifying Ivy City neighborhood.
They stand out in other ways: 12-inch-thick exterior walls and triple-pane, imported-from-Ireland windows offer more than double the insulation required of new homes. In lieu of a furnace, tiny, wall-mounted Mitsubishi units provide heating and cooling. (See related blog post: “Laying the Foundation for Sustainable Housing in D.C.“)
The passive standard is buoyed by efforts to fight climate change, because buildings account for 40 percent of total U.S. energy use and 10 percent of its greenhouse gas emissions.