This is about as far from its Dwell rap that modular housing can come: a 6,300-square-foot McMansion in the tony DC suburb of Bethesda, Md. Called Bradley Green Show Home, this LEED-certified prefab princess—”systems built construction,” as Sandy Spring Builders says—took four months to complete once the foundation was laid. That being said, it only took one day for the home to be set, with portions being stacked on each other like Legos. Blink and you’ll miss it. Information from curbed.com http://www.youtube.com/watch?v=veNT1Ox2pO8&feature=player_embedded#!