Home & Garden

Treehouse magic: no age limit here

Clad in fish-scale siding and a steep curved roof, this whimsical structure embodies the storybook appeal common to many treehouses.
Clad in fish-scale siding and a steep curved roof, this whimsical structure embodies the storybook appeal common to many treehouses. Pete Nelson

As kids, most of us probably never gave that much thought to building or remodeling the homes we lived in; that was the domain of the adults. They made the decisions about swinging a hammer, browsing wallpaper swatches or meeting with contractors about a project.

If we headed outside, however, the rules changed. Swept up in imaginative play scenarios, we could fashion makeshift forts or convert old sheds into secret hideouts. If we were ambitious and skillful enough, and had access to some simple tools and materials, we could tackle the ultimate childhood adventure — building a treehouse.

Years later, it seems that the fascination with arboreal dwellings has followed many of us into adulthood. Is it some evolutionary remnant, a leftover scrap of primitive psyche that beckons us into tree branches? Or something simpler, like how the world looks so different from 15 feet up?

Pete Nelson, a professional treehouse designer and builder, might have an opinion, but mostly he seems too busy enjoying himself to care about the subtleties of motivation. For him, treehouses have an intrinsic magic and appeal — no explanation needed. Thanks to that enthusiasm, Nelson has emerged as one of the foremost practitioners and proponents of the craft, even landing a gig as host of the television program Treehouse Masters on Animal Planet. A decade ago, he wrote his first book on the subject, highlighting treehouses from around the world.

His most recent effort, called Be in a Treehouse: Design/Construction/Inspiration, blends great examples of completed projects with guidelines on design and construction techniques, including some specialized hardware developed to accommodate the newfound interest in treehouses.

The inclusion of this more technical material sets this volume apart from Nelson’s earlier books, but it’s clear he still considers treehouse building a partly philosophical undertaking. The challenge, he says, is “how to connect respectfully and responsibly to living trees,” and the how-to core of the book deals mostly with this part of the process. Getting a solid and stable platform is fundamental; once that’s done, the “shell” and decor of the treehouse can go in many different directions.

The design and engineering options involve critical details that will vary with each site and each tree specimen, but grasping some basics will let you know if you and your tree are good candidates for a treehouse adventure:

▪ Run the numbers: Most treehouse floor plans occupy between 80 and 200 square feet, with platform height typically ranging from 10 to 20 feet off the ground. Support can come from one tree or several, with minimum trunk diameter of 18 inches at the attachment points. Have a professional arborist evaluate the trees for suitability.

▪ Suitable tree species: Nelson’s most recommended trees species are ash, beech, red or white cedar, cypress, Douglas fir, elm, most oaks, most maples, redwood, spruce and sycamore. Birch, cherry, hemlock, hickory, pine, poplar and walnut are among the acceptable alternatives. Avoid alder, aspen, box elder, cottonwood and swamp oaks.

▪ Make it legal: Nelson relates a cautionary tale of his earliest treehouse projects, when he bypassed local building officials and permit requirements. These were unconventional structures, he reasoned, thinking it was easier to ask forgiveness than get permission. The result was wasted effort, costly tear-downs, and a strained relationship with the county building department. Now he does everything by the book and has partnered with area inspectors and officials to develop structural codes and guidelines for treehouse construction. The lesson: Submit a plot plan and elevation drawing the same as you would for any structure, be flexible and get approval before you start building.

▪ New-generation hardware: Nelson and other treehouse builders have learned how critical it is to accommodate tree growth and movement, and they’ve developed new hardware to make connections to trees stronger and less intrusive. A key component is the TAB (tree attachment bolt), a stepped and threaded steel rod that supports platform beams. The TAB allows growth of new tree tissue and pairs with other steel hardware to allow tree movement due to winds. This and several other new components have considerably widened the design options for treehouses.

Nelson’s take on treehouses seems perfectly balanced. There’s a healthy respect for the structural, technical and safety issues, while the sheer fun of the experience never gets lost amidst these necessary reality checks. Dozens of treehouse examples from around the world are featured also, so there’s no shortage of inspiring ideas to feed your adventure. Every dream-turned-reality needs a foundation, and this book is a solid one.

Book Information

“Be in a Treehouse: Design/Construction/Inspiration” by Pete Nelson; Abrams Books; 2014; $37.50; hardcover, 224 pages; 212-206-7715; www.abramsbooks.com