Please scroll down to view a series of images that will give you a good idea of how the treehouse was constructed. Click any image to see it larger. These images, plus over 175 more, are all found in our book Treehouse Chronicles. If you would like to purchase a signed copy of the book, please click the title and you can buy direct from the publisher.
This is a front view of the finished treehouse in the fall of 2004. It is 300 sq. ft., has two stories, is 21 feet off the ground, weighs 6000 pounds, has 21 windows, 2 spiral staircases, a woodstove, and a drawbridge, and is suspended from cables. There are no fasteners in the trunk of the tree.
This was my original sketch for the treehouse—banged out quickly just minutes after the inspiration hit me in the spring of 2001. My first thought was a tiny building, just 8’x8’, with just a chair and desk—a place to work (and take naps).
This is a schematic of the treehouse platform showing the steel collar, the horizontal truss members, the interior and exterior rim joists, and the floor joists.
A primary goal was to build the treehouse without putting any metal fasteners in the trunk of the tree. We did this by suspending a steel collar from cables that ran in conduit through a fork in the tree 37 feet up. Six timberframe trusses where then bolted to the collar and braced against the tree. Treehouse experts tell us that this simple and strong (15+ tons) solution is unique (at least in the US) and at least one treehouse engineering company will be implementing our design into some of their projects.
This close-up shows how the collar and trusses are braced against the tree with upside-down wedges. Putting the wedges upside-down adds another level of strength and security. (The wedges are held in place with nylon webbing tied to branch stubs.)
This drawing shows the trusses suspended in the tree.
The platform for the treehouse is a maze of timbers all held together with mortise and tenon joinery. The six large timbers (5”x7”) that form the radii of the hexagon are the tops of the triangular trusses. Resting on top of them are the interior and exterior rim joists (5”x5”), and mortised into those are the common joists (3”x5”).
An action shot from early in year three of construction—putting on the tongue-and-groove pine siding. Over the next three years, the siding aged beautifully from the screaming yellow of new wood to the faded grey of an old barn.
As much as possible, we made components of the treehouse from “found materials” from the surrounding forest. We made the spiral staircase that leads from the first floor to the second floor from a peeled pine tree, with treads milled (with a chainsaw) from a second tree. Like the treehouse, we built these stairs without any metal fasteners.
After suspending the six main trusses, we spent several weeks leveling and bracing the trusses and then installing the rim joist—all from the comfort (?) and security of ropes and climbing harnesses.
Every treehouse needs a drawbridge. Our is a simple affair requiring only plumbing supplies, hinges, cables, pulleys, granite counterweights, and a clothesline tensioner. It’s a long story.
If you were to cut the treehouse in half, this is what it would look like.