Tree houses are for everyone with imagination. Elevate your building skills with these tree house building tips from experienced builders, including attachment techniques, site choice and more.
Climbing trees has always been part of human history, allowing us to escape floods, saber-toothed tigers and intruders (especially parents with chores in mind). Building tree houses has long been part of human history, too. In that spirit, we’ve gathered tree house building tips, project ideas and photos from professional tree house builders. Maybe something here will inspire you to build the tree house of your dreams, for the special kids in your life or as a way to escape from modern day saber-toothed tigers and chore-requesting spouses.
“You get a different perspective when you’re up in a tree. First of all, nobody can find you because nobody ever looks up. And when you’re up there, you’re able to look up, down and all around—it’s another world up there.” Michael Garnier, professional tree house builder
Choose a healthy, long-lived hardwood for maximum support, with load-bearing branches at least 8 in. in diameter (larger if the species is a softwood). The best trees include maple, oak, fir, beech and hemlock.
You don’t have to build it very high, just high enough so nobody gets a bump on the head when walking underneath it.
Keep weight and stability in mind
Build the platform as close to the trunk as possible and add diagonal bracing for extra strength to support uneven loads. Put the load over the base of the tree, not on one side. For heavy tree houses, consider spreading the weight among several trees.
A tree house will act as a sail in strong winds, which can add a large load to the tree’s roots. In high-wind areas, build your tree house in the lower third of the tree.
Don’t Restrict Tree Growth
Don’t constrict branches with rope, straps or wire. This can strangle the tree. Add spacers between the beams and the tree to allow movement.
Use extra-long large bolts. This leaves most of the shaft exposed so you can mount items on the ends and lets the tree grow over the shaft (see “Use the Right Fasteners” below).
Allow a 5 cm gap around the tree if it passes through the floor and a 8 cm gap if it passes through the roof.
Level the floor
It’s much easier to build the rest of the structure if the floor is level and can support the entire weight of the tree house. Consider these methods:
- Lay beams across the branches and shim until level.
- Run the beams between trunks of different trees.
- Cantilever the beams out from a single trunk and support them from above or below.
Use the right fasteners
Don’t use too many fasteners. One large bolt is better than many screws or nails. You get the same strength but with fewer puncture wounds to the tree. Whenever possible, perch your tree house on top of fasteners rather than pinning beams to the tree. This gives the tree room to move and grow.
You can order floating brackets and tree house fasteners from specialty suppliers such as or special-order them from home centers . These bolts are pricey but they allow the tree more room to grow (they can support heavy loads up to 10/15 cm from the tree) and they hold more weight than normal bolts.
Building a tree house is a wonderfully whimsical and romantic idea. But it’s important to go into it with your eyes open. Keep the following issues in mind:
Tree houses do damage trees. Foot traffic compresses the soil, which is bad for the roots. Adding weight in the branches can also stress the tree roots, and fasteners can cause infection. Most trees will survive this abuse, but think twice before you build in a treasured tree.
To minimize tree damage:
- Consider using one or two supports to take stress off the tree.
- Make the fewest punctures necessary to support the tree house safely. Any damage to the bark of the tree is a potential entry point for disease and bacteria.
- Don’t put fasteners too close together, which can weaken that section of the tree. Use at least 3/4-in. bolts spaced at least 18 in. apart vertically and 12 in. apart horizontally.
- Avoid slinging cables and ropes over branches. They cut through the bark as the structure moves.
Kids can get hurt playing in a tree house. Don’t build too high and make sure to build safe, strong rails. Also, nobody should be in a tree house in high winds or lightning.