People who know and work with Pete Nelson describe him as a tree whisperer. For his part, Nelson lets the trees do the talking. He's a world-renowned treehouse designer and builder, and this series documents the work he and his team of craftsmen - including his son Charlie - do to create incredible homes and businesses in nature's canopy. Pete uses a combination of science and art to realize clients' sky-high aspirations of magnificent multibedroom treehouses with elaborate kitchens and bathrooms, or simpler, peaceful one-room escapes. Other backyard above-ground spaces featured in the series include a spa retreat, a brewery, and a honeymoon suite. "We awaken that inner child who dreams of living among the trees," Pete says.