Matthew and Meghan Tanner are growing their family but downsizing their house. You could say they're "thinking outside the box" when it comes to cutting their budget to make room for their second child. They've contracted a tiny house builder to create the shell of their 220-square-foot home, while they plan to complete most of the unique interior. Key features include double lofts separated by a catwalk, a floating baby carrier, a couch that transforms into a dining room and a custom family-size walk-in closet.