How to Build a Treehouse in the Backyard
A chain hoist helped raise a heavy pile of green oak, barn siding and pine flooring up into this formerly unoccupied Kentucky coffee tree.
It's a common-sense rule of treehouse construction: Make it lightweight. "So I felt some stirrings of anxiety when the stocky, bearded sawmill owner pulled up to the house with a flatbed trailer stacked with oak timbers. Full of water, densely grained and smelling like bourbon, the rough-cut framing lumber I'd ordered spanned 18 feet and looked like bridge supports. As we offloaded the first 2 x 8, each of us taking an end in hand, I smiled doggedly to mask the strain I felt. He peered over the garden fence past the lilac bushes, and politely asked," "What kind of treehouse are you building?"
"One thing was certain: It wouldn't look much like the rickety aeries of my childhood, hammered together out of whatever construction scraps and packing crates we neighborhood kids could scrounge up. (The most ambitious of these was a three-story fort spanning a creek and topped by a crow's-nest made from an old kitchen chair nailed to the trunk.) This time, I'd enjoy the advantages of milled lumber and a carpenter's square and level, not to mention power tools. Yet I hoped to match the spirit of those earlier tree forts with a rustic structure where my children could waste their afternoons dreaming up rules to games I'd never understand or even hear about."
"As kids, my friends and I never bothered with plans. We had an abundance of trees and were eager to start hammering. Today, there are exactly four mature trees in our backyard. I consider them all irreplaceable—at least in my lifetime—so after deciding to build a treehouse, I thought long and hard about where to put it. The ideal host was a 70-foot-tall Kentucky coffee tree standing alone in a corner of our small lot. It rises 15 feet before its trunk sprouts into a balanced, oval-shaped crown that filters sunlight through its leaves like flour through a sifter."
As an adult and a conscientious neighbor, I also thought hard about what the treehouse would look like. I wanted something that would not seem out of place in the historic Virginia downtown where we live. No cheap-looking plywood box or precious playhouse on stilts would do. The structure would be modest in size, and the materials would have an outsize effect on how it looked. I asked my friend John Foster, a capable craftsman who built the log cabin where he lives, for advice.
The scrap-wood citadels of my childhood (above, left) lacked a certain sophistication that comes with actual planning. After struggling to draw my new design on graph paper, I built a model out of cardboard (above), specifying details like a Dutch door, lap siding and an observation deck on one side.
Building a treehouse is a lot like any other construction project, with one main difference: Instead of a foundation, a treehouse rests on a platform. The platform should be sturdy enough so that whatever sits atop it—gingerbread Victorian, open-sided play hut or, in my case, rustic cabin—doesn't attach to the trunk. That minimizes damage to the tree and keeps the swaying on a windy day from prying apart the structure. It also, frankly, is a mark of craftsmanship—the difference between banging together boards as a kid and doing it right, with a measure of adult skill and judgment.