Just 80 miles east of Manhattan in the hamlet of Riverhead, on Long Island, a pleasant, if unassuming, ranch-style house is scheduled for construction. To the casual eye, it will be so ordinary as to be scarcely noticeable, although the 1,400-square-foot, three-bedroom house at 34 Millbrook Lane is destined to be anything but. The main structure of this dwelling is to be built, not by a crew of a dozen or more workers and countless machines spewing carbon dioxide into the air over several months, but by a robotic arm hoisted on a single truck in just three days. The installation of the roof and finishings are scheduled for completion a mere three weeks later. Significantly, because of its lower production cost, the home is listed at $299,999—about half of what a comparable property in the area would be.