With the addition of a striking, two-story "living hub," architect Rebecca Caldwell of Maytree Studios adds the finishing touch to her brother's Sunshine Coast home in Queensland, Australia. The double-height, 1800-square-foot addition, as designed by Caldwell of Maytree Studios and built by her brother, hosts generous kitchen and living areas with ample connection to the outdoors, as well as an upper mezzanine floor that can be flexed for work or play.