Steve and Jeri Wakefield had the idea nine years ago to build an elaborate tree house for their grandsons, Lincoln and Sullivan Scott, in their Dallas backyard. They hired architect and family friend James Curvan to craft a whimsical playhouse with steeply pitched gables, multilevel decks and staircases. To keep pace as their grandsons grew, the Wakefields added exciting upgrades, including a climbing wall, rope ladder, suspension bridge and zip line.“To make a good tree house, you have to think like a kid and take care of the tree,” Curvan says. A series of steel posts, which Curvan painted the color of bark, support the child-size structure, while a giant pecan tree grows through the house but does not bear any weight. With their grandsons all grown up now, the Wakefields invite children from all over the neighborhood to their tree house mansion to play king or queen for a day.