The Mikado 2 sofa by Hans Hopfer for Roche Bobois is a bright and cheery centerpiece in the otherwise sedate living room. The nubby wool Photon rug from Design Within Reach warms up the expanse of concrete. The framed drawing is by the Los Angeles–based artist Daniel Brice. Huge sliding doors open the house to the outdoors and virtually double the Burtons' living space.  Photo 5 of 8 in When Prefab Is Painless