The Treehouse Guide Structure and Safety
The most important part of any treehouse is not the building. It is the tree. A treehouse has to live alongside something that grows, moves and changes over time, and a good design takes all of that into account from the start.
Why rigid fixings cause problems
Trees move in the wind, their trunks and branches thicken every year, and their roots develop. A structure that is attached rigidly to a tree without allowing for movement puts unnecessary stress on both the tree and the building. That is why specialist treehouse construction is different from simply building a conventional structure and bolting it to a tree. The connections and the support system have to accommodate movement.
How much clearance we leave
The age, species and growth rate of the tree determine how much room we leave around the trunk. For a mature, slow growing tree such as an oak, we typically allow a minimum gap of 60mm between the trunk and the treehouse floor, decking or roof. For younger or faster growing trees, a larger clearance is needed to allow for continued growth and movement.
Keeping the gap safe
Where a larger gap is needed, safety has to be considered too, particularly where young children will be using the treehouse. A big opening around a trunk can trap an arm or a leg. Where appropriate, we install a thick rope or a similar flexible barrier around the opening. It reduces the risk while still giving the tree the space it needs to grow and move.
After the build
The tree and the treehouse carry on interacting for as long as they stand together, so the parts of the structure attached to the trees should be inspected regularly. Movement in the wind puts forces on the braces and fixings, and regular inspection means anything that needs attention is picked up early.
