How to Build a Tree House
Advice and tips for building, attaching and furnishing your home in the treetops. Learn how to build a treehouse from experienced builders.
Overview: The inspiration of tree houses
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 how to build a tree house tips, project ideas and photos from TFH readers and 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. Learn how to build a treehouse from experienced builders with some treehouse plans. Enjoy!
“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
Out‘n’About Treehouse Treesort
Tree house and suspended walk
This tree house has electricity and the access is a walkway hung on cables.
Designer tree house
A tree house can be a place for the imagination, as shown in this design.
How to Build a Tree House Tip 1: Site considerations
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.
How to Build a Tree House Tip 2: Keep weight and stability in mind
Build a tree house 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.
“I built a tree house for my kids in our backyard (Photo). It was tricky getting the roof in place and, of course, nothing is square. They drew the wall design on regular paper, and we transferred the pictures to the walls, using a grid method. We replace the old pictures with new ones each year.” Sean Milroy
Single trunk construction
When building on one main trunk, level the main platform by cantilevering the beams and supporting them from below.
Building Tip 3: 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,” Tip 6, below).
Allow a 2-in. gap around the tree if it passes through the floor and a 3-in. gap if it passes through the roof (photo).
Leave gaps around the tree
To accommodate tree movement and growth, allow gaps around any branches or trunks that penetrate the tree house.
Building Tip 4: 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.
“I wanted my kids to experience the same fun I had in my tree house as a kid but without the risk of killing themselves—like I nearly did.” Brenton LaFleur
Level and sturdy
To keep a large tree house stable, center the load over the trunk and spread the weight among several branches.
Building Tip 5: Build sections on the ground and hoist them into position
From one tree house builder:
“I built it in my driveway and used a friend’s backhoe to lift it up on the joists I’d hung in the trees (Photo 1). The morning of ‘the big lift’ was quite exciting. We served bagels and coffee in the driveway for people who came to watch.”
And from another: “I assembled the platform and house on the ground, then disassembled them. After attaching the supports to the trees, I lifted the platform piece by piece and assembled it on the supports (Photo 2). An extra set of hands was needed only to raise the four walls and two roof sections. Final assembly took place in the trees.”
Photo 1: The big lift
It’s easier and safer to fabricate the main sections on the ground and then hoist them into position.
Photo 2: Piece by piece
If branches penetrate areas of the tree house, complete the construction up in the trees.
We Believe You, Nate!
“I am 13 years old and I’ve been building this fort for a few years now. I’ve had no help from adults at all. I’ve got a toolbox full of tools, plus I have a DeWalt drill and a jigsaw with a laser. I really want the world to know about my fort. Remember, I’m only 13 and I built this myself. If you don’t believe me, you can e-mail my mom.”
Building Tip 6: Use the right fasteners
Don’t run bolts through the tree. Lag bolts cause less tree damage than through bolts.
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.
Even for smaller, lighter tree houses where the load is spread over three or four attachment points, consider using 1-in.- or 1-1/4-in.-diameter lag bolts.
You can order floating brackets and tree house fasteners from specialty suppliers such as garnierlimb.com or treehousesupplies.com or special-order them from home centers (Photos). These bolts are pricey (about $100 each) and often require special tools. But they allow the tree more room to grow (they can support heavy loads up to 5 in. from the tree) and they hold more weight than normal bolts.
Floating bracket support
Allow for flexible supports, especially if you use more than one tree, so that trees can move in the wind. Special floating brackets allow the tree to sway.
Heavy duty custom bolt
Large, strong custom bolts can support tree house beams with only one puncture point in the tree. These specialty tree house fasteners (known as TABs or GLs) are worth considering if you want your tree house to last more than a few years, you want to keep tree damage to a minimum and the tree house you’re building is large.
Minimize tree damage by perching beams and braces on top of specialty fasteners instead of pinning them to the tree.
Building Tip 7: Checklist of cool accessories (to buy or make)
Water cannons and other toys appeal and embellish children’s imaginations.
- Zip lines
- Rope swings, ladders and bridges
- Speaking tube
- Clothesline pulley with bucket between tree house and kitchen for frequent snacks (or to lower to the ground to fetch provisions)
- Pirates’ treasure chest
- Tennis ball/potato launcher
- Water cannon
- Fire pole or slide
- Trap door
- Solar-powered lights or lanterns
- Fold-down benches and tables
Building Tip 8: Beware of the dark side of tree houses
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.
Neighborhood concerns and municipal regulations
Do you need a building permit? It depends on local laws and the nature of your tree house. If you’re considering building one that will be visible to your neighbors, discuss it with them in advance to avoid problems. Often, a municipality becomes involved after a neighbor complains. Stay away from boundary lines and don’t build your tree house where it will infringe on a neighbor’s privacy.
Kids can get hurt playing in a tree house. Don’t build higher than 8 ft. and make sure to build safe, strong rails. Also, nobody should be in a tree house in high winds or lightning.
Tree House Destinations
Type “tree house hotels” and “tree house destinations” into your browser, and you’ll be dazzled by the number of amazing tree houses you can visit all over the world. Here are a few close to home:
Vertical Horizons Tree House Paradise
Vertical Horizons Tree House Paradise, a B & B tree house resort located in southern Oregon. Three state-of-the-art tree house guest quarters. Also offers tree climbing and salmon run and mushroom-picking expeditions. treehouseparadise.com
Out‘n’About Treehouse Treesort
Out‘n’About Treehouse Treesort in Takilma, Oregon. Michael Garnier’s B & B tree house complex with 13 custom guest tree houses including Treezebo, Serendipitree and Pleasantree. Garnier also offers tree house building workshops, a zip-line course, a canopy walk and more. treehouses.com
Great Books and Web Sites
Treehouses: The Art and Craft of Living Out on a Limb and Home Tree Home by Peter Nelson
Build Your Own Treehouse by Maurice Barkley