Completed in 2011, the other end of the structure is a four-story, 4, 000-square-foot house with under-floor heating, solar panels, low-energy appliances and the latest in triple-glazed windows.

WSJ: Inside Story: A Modern Farmhouse in Austria

In Hamburg, construction is moving forward on the Renewable Energy Bunker, an abandoned WWII bunker that is being retrofitted with enough solar panels to provide heating for 3, 000 households and electricity for 1, 000 homes.

ENGADGET: Inhabitat's Week in Green: flying electric car, 3D-printed livers and a two-story-tall bike

As well as using wind turbines to provide electricity, and straw-burning plants to provide heating, some islanders have solar panels on their roofs and others warm their homes using geothermal energy and the heat given off by fresh cow's milk.

CNN: Striking a blow for wind power

Nevada's first platinum-certified LEED (Leadership in Energy and Environmental Design) buildings stand proudly here, constructed of recycled materials and rammed-earth walls, with passive cooling, renewable heating, reclaimed water and solar-electricity panels, all harvesting clean energy.

BBC: Discover life in the Nevada desert

Energy efficient appliances and windows, foam insulation, heating and cooling systems powered by geothermal, solar panels, and wind mills have all quietly begun invading new construction, particularly in the luxury end of the market.

FORBES: From Pet Spas To Digital Brokerages, The Most Unusual Housing Trends To Track In 2013

The laundry list of green features of each Oil Silo Home is exhaustive: super-thick insulated wall panels, rainwater recycling systems, rooftop gardens, natural ventilation, EV charging stations, radiant floor heating, green walls, and the list goes on and on.

FORBES: Written by Matt Hickman