Jim Heim’s tree house is play-ready in any season. In warm weather, it’s an outdoor playground where kids can swing, slide and climb. When winter comes, the insulated and heated house gives them a warm play space. No part of the tree house is supported by the tree. But since it’s intertwined with the tree, swaying branches could do a lot of damage. To prevent that, Jim dreamed up a clever solution: High above the tree house, Jim lashed the branches together with steel cables. That limits branch movement on windy days and has kept the structure safe and solid for many years.