Scrivenings Mansion

Found this awesome photo on Flickr by Scrivenings of a multistory tree house.

It appears to be attached to three small trees: two in the front and one in the rear. Normally, trees this diameter are a bit on the small side; however the design and floor arrangement seem to compensate for the limitations. There are a few interesting build considerations necessary when using small sized trees:

First, building the house low helps increase stability with small trees. Low has a down side in that it is very important to allow for independent movement on each of the tree trunks. Don’t make the mistake of thinking small trees are not strong. Wind induced motion at the top of the trees has the advantage of leverage and can break most rigid deck structures. And small tree tend to move more in the wind than large ones.

The photo offers a view of one solution to the tree movement problem. Under the viewing deck you can see a floating beam design. Each tree has a metal bracket attached that holds the beam up and yet allows it to slide laterally to accomodate tree movement.

Second, notice that the trees are braced across three levels: tree house floor, upper deck, and top most brace. I assume to top most brace prevents the trees from splitting apart too much, a problem exageratted by the weight of the main floor. And, the brace to the rear tree is also intended to keep it vertical. Small trees are rarely straight up and down, and any tendency to lean will be exaggerated when the weight of the stucture is placed on it. And, the more a tree leans, the more the weight wants to push it over, and this can lead to a catastrophic support failure.

Third, there is always an anchor for the deck. Notice that the rear ‘tripod’ tree is attached with knee braces and is probably anchored directly to the deck floor. In a three tree design, it is common to securely anchor the house to one tree and let it ‘float’ on the other two. This provides a range of motion needed to accomodate tree trunck sway and yet stability to keep it in one place.

On an end note, I’d also like to mention the artistic considerations built into this treehouse. The railing in the front filled with branch arrangement is very organic and I can appreciate the amount of time that must have gone into making that. The rope ladder is cool and compact. And, I like the little bird houses up on the top brace! Very friendly, very functional.