A ‘postcard from the future,’ this zero-energy park building creates as much energy as it uses

OAK PARK, Illinois — Plastic pipes snake down 460 feet into the earth, drawing up enough warmth to heat a 7,700-square-foot building — even on the coldest days of winter.

Rooftop solar panels can produce twice as much electricity as the building needs.

And don’t crack those triple-layered windows: Palm-sized sensors track the amount of carbon dioxide being exhaled into the room and send in fresh air whenever it’s needed.