After realizing they had spent upward of $58,000 in rent after just four years, Malissa and Chris Tack opted to downsize.Malissa, a 3D designer and animator, designed their tiny, solar panel-equipped house from the ground-up. And along with husband Chris, the two completed construction of their new home—all 140 square feet of it—in just over a month.NPR's Science Friday recently profiled the Washington couple, who now pay just a dollar a day for electricity—and that's in the dead of winter. But can a couple really live together in such a small space without going crazy? Apparently it's simple. What do you do when you need space from one another? "You actually open the front door and you walk out," Malissa says.