#1 Home Improvement Retailer

Project Guide

How to Build a Treehouse

Item(s) have been added to cart.

Choose a Tree
A couple find a stable tree for a treehouse.

The first step to building a tree house is to find the right tree. 

Choose one that is sturdy enough to withstand the weight of your new treehouse, as well as any visitors that may occupy the space. Ideally, you’ll want a tree with a distinct “y” shaped branch, but there are other things to consider:

  • Type: Hardwood varieties like oak, maple and hickory are ideal for treehouses.
  • Height: The tree should be high enough for a nice view, but consider the safety of the builder and children as well. We recommend staying between 6 to 10 feet high.
  • Branches: The branches should be strong and thick enough to bear the structure.
  • Quality: Take care to choose a tree that is not damaged in any way. Also avoid ones with shallow roots since they’re more vulnerable and have a weaker foundation.

Create a Blueprint
Design plans and blueprints for building a treehouse

The next step is to draw up treehouse plans as accurately as possible. Creating a blueprint will ensure you have the right materials during the build. 

  • Measure the height from the ground to the platform location and then measure how large you want the platform. 
  • Include these dimensions on your plan. Also include ideas for walls and railings. These will provide extra safety for the future treehouse occupants.  
Build the Foundation
Two people measure and build the foundation using concrete blocks.

Now it’s time to build the foundation of your treehouse. 

  • Start by setting your 4 x 4 posts on the concrete deck blocks, using scrap lumber to help hold up posts until they are connected.   
  • Once posts are on the blocks, connect them by using 2 x 8 bands. 
  • Use your level to make sure they are lined up correctly. Then, use your framing nailer and 3-inch framing nails. 
Layout the Platform
A man and woman lay out decking boards to determine the direction.

To build the platform, you'll need to determine which direction you want to run your decking. This will determine the direction of your floor joists, which should run perpendicular to the deck boards. 

Attach Floor Joists
Joists are attached to deck boards.

 Now it's time to attach the floor joists to the tree. 

  • Pre-drill the tree and the 2 x 8's prior to attaching them to one another, as it will make it easier to install and decrease the odds that the boards will crack.
  • Once drilled, use an impact wrench to tighten the screws. Keep in mind, your lag screws should be at least 6 inches long. 
  • Now, add the remaining floor joists at 16 inches from the center. 
Attach Joist Hangers
Joists are attached to the boards.

With the joists in place, add joist hangers using your hammer and 1-inch galvanized nails.

Cut Angle Braces
A man uses a miter saw to cut angle braces from 4 x 4's.
  • Next, using your miter saw, cut  your shorter 4 x 4 posts for angle braces. The braces will add extra stability to the foundation.
  • Cut the posts at a 45-degree angle. Each angle brace should be about 2 feet long. 
  • Attach to the foundation post with 3-inch deck nails. 
Attach Deck Boards
A nailer is used to attach deck boards to a platform.
  • Next, connect the deck boards to the platform using 2-inch wood nails. 
  • Be sure to measure each piece, as you'll have to cut around tree and the posts to fit. 
Build the Frame
A couple builds the frame for a treehouse.

It's time to move on to the walls. 

  • Measure and cut your 2 x 4 studs to build the treehouse frame. You'll want to build the frame based on the perimeter of the platform and your desired height of the roof. 
  • Attach to the platform using your framing nailer and 3-inch nails. 
  • Next, add vertical studs at 16 inches on the center. 
  • Remember to frame out where you've planned for doors and windows. 

Tip: Install temporary 2 x 4's across the top to keep the walls plumb. 

Build the Roof
A man attaches a roof to a treehouse.
  • Using your 2 x 6 lumber and saw, make the ridge beam. 
  • Attach the 2 x 4 rafters at 2 feet, on the center. The rafter should reach from the top plate of the walls to the ridge beam. 

Tip: Stand 2 x 4 studs up to support the ridge beam while you are attaching it to the frame. 

Frame the Walls
A man uses a level to check the walls of a treehouse.
  • Frame up your gable end walls from the floor to the rafters using your 2 x 4 studs. 
  • Once attached, you can remove the temporary 2 x 4's. 
Install Siding
Couple attaches siding to a treehouse frame.
  • Now that your walls are in place, begin installing the siding. 
  • Measure and cut the siding to your desired fit. 
  • Attach using your framing nailer and 2 3/8-inch framing nails. 
  • Nail the siding to the gable end walls. 
  • Use a reciprocating saw to remove any excess wood. 
Cut Holes for Doors and Windows
A woman uses a reciprocating saw to cut holes for doors and windows.

With your reciprocating saw, cut out holes for doors and windows. 

Add Roof
A roof is attached to a treehouse using a nailer.

Now, you're ready to add a roof to your treehouse. 

  • Cut the plywood sheathing to fit and attach it to the rafters, using your framing nailer and 2 3/8-inch nails. 
  • Be sure to leave enough room for the tree and enough plywood for a 6-inch overhang. 
Add Trim to Doors and Windows
A couple attaches the trim to the doors and windows.
  • Give your treehouse a more finished look by installing trim around the doors and windows. 
  • You can create the trim using 1 x 4 and 1 x 6 lumber. 
  • Attach the trim using your nailer. 
Add a Handrail
A woman attaches a handrail.

For safety purposes, it's a good idea to add a handrail to your treehouse. 

  • Attach a pre-built handrail section around the deck area. 
  • Leave space for the ladder and entrance. 
  • Connect railing to the posts using rail connector brackets. 
Attach Ladder
A woman attaches a ladder to the treehouse.
  • Space the rungs for the ladder about 7 to 10 inches apart. 
  • Using 2 x 4 lumber, cut the desired amount of steps. 
  • Attach using your drill and 3-inch deck screws. Pre-drill the holes to make drilling easier. 
Enjoy Your Treehouse
A couple admires their finished treehouse.
  • Once your ladder is complete, your treehouse is built. You may choose to stain it or leave the lumber as-is. 
  • Now, enjoy it with your family for years to come. 

Learning how to build a treehouse can seem overwhelming, but it can done safely with the right supplies and instructions. The Home Depot is your DIY headquarters. Ready to get started on your treehouse? Use our project calculator to find the right amount of materials for your project.