Tricked-Out Treehouses

These aren’t your typical backyard treehouses. Some nature lovers have constructed amazing tree hideouts so they can experience life in the forest in comfort. That’s what the Gardner family did.

When the family moved to their new home on a dairy farm in Waxhaw, North Carolina, their daughter Anna had one request: to have a treehouse. “It was my idea, because I never had a backyard playset like other kids in my old neighborhood,” says Anna, who is now 14 years old.

These aren’t your everyday backyard treehouses. Some nature lovers have built amazing tree hideouts so they can enjoy forest life in comfort. That’s what the Gardner family did.

The family moved to a new home on a dairy farm in Waxhaw, North Carolina. That’s when their daughter Anna asked for one thing. She wanted a treehouse. “It was my idea, because I never had a backyard playset like other kids in my old neighborhood,” says Anna, who is now 14 years old. 

One day, Anna’s dad, Alan, and mom, Gwen, saw Treehouse Masters on the cable network Animal Planet. The series, now in its ninth season, follows Nelson Treehouse and Supply, which designs and builds extreme treehouses. Anna’s dad contacted the company, based in Washington State, to create a treehouse big enough for his whole family. Its construction was featured in one of the show’s episodes.

The Gardner treehouse (see Treehouse Features) sits about 3.5 meters (11 feet) off the ground nestled between tree trunks. It has a main room with a small kitchen and dining area, a lounge, and an outdoor balcony. Anna has a secret loft in the ceiling where she hangs out with friends. There’s also a bed suspended above the floor by ropes and surrounded by windows for spectacular views of the forest.

Anna’s dad, Alan, and mom, Gwen­, were watching TV one day. They saw Treehouse Masters on the cable network Animal Planet. The series is now in its ninth season. It follows Nelson Treehouse and Supply, which designs and builds extreme treehouses. Anna’s dad called the company, based in Washington State. He asked the Nelson team to create a treehouse big enough for his whole family. It was built on one of the show’s episodes.

The Gardner treehouse rests between tree trunks about 3.5 meters (11 feet) off the ground (see Treehouse Features). Its main room has a small kitchen and dining area, a lounge, and an outdoor balcony. Anna has a secret loft in the ceiling. She hangs out with friends there. The treehouse also has a bed. It hangs above the floor from ropes and has windows all around it. That provides amazing views of the forest.

“People love treehouses,” says Daryl McDonald, a project manager who has designed and constructed many treehouses for Nelson Treehouse and Supply. “They’re a way to get closer to nature.” And since nature is an integral part of the structure’s design, building a house perched on tree branches requires a lot of specialized engineering expertise.

“People love treehouses,” says Daryl McDonald. He’s a project manager who has planned and built many treehouses for Nelson Treehouse and Supply. “They’re a way to get closer to nature.” Nature is an important part of the design, since the house is built on tree branches. And that calls for a lot of special engineering knowledge and skill. 

To start designing a treehouse, McDonald first visits a client’s property. He walks around looking for trees with trunks that are at least 31 to 46 centimeters (12 to 18 inches) wide, so they’re strong enough to support a treehouse. The trees also need to be 2 to 4 m (6 to 12 ft) apart. That’s so the building’s vertical load is distributed as evenly as possible between the trees. A vertical load equals the mass of a structure multiplied by the downward force of gravity (see Standing Tall).

To start planning a treehouse, McDonald visits a customer’s property. He walks around and looks for the right trees. Their trunks must be at least 31 to 46 centimeters (12 to 18 inches) wide, so they’re strong enough to hold a treehouse. The trees also need to be 2 to 4 m (6 to 12 ft) apart. That’s so the building’s vertical load is spread as evenly as possible between the trees. A vertical load equals the mass of a structure multiplied by the downward force of gravity (see Standing Tall). 

“Most traditional homes have a cement foundation to support the structure above,” says McDonald. “But the trees act to support the load of a treehouse.”

It’s also important that only healthy, strong trees are chosen to support a treehouse. McDonald says that he looks for any sign of fungal growth on a tree. If he spots any mushrooms growing on a trunk, he knows there’s likely moisture and decay within the wood. The trees need deep roots, as well. Trees like willows and cottonwoods, with shallow root systems, could easily topple over from the treehouse’s load. Oaks, poplars, maples, firs, and eastern hemlocks are some of the best to build in. The Gardners’ treehouse, for example, was built among a group of trees that included oaks and poplars.

“Most traditional homes have a cement foundation to support the structure above,” says McDonald. “But the trees act to support the load of a treehouse.”

McDonald chooses only healthy, strong trees to support a treehouse. He says that he looks for any sign of fungus growing on a tree. Mushrooms on a trunk are a bad sign. That tells him the wood probably is rotting inside from moisture. The trees also need deep roots. Trees like willows and cottonwoods have shallow roots. Those trees could easily fall over from the treehouse’s load. Oaks, poplars, maples, firs, and eastern hemlocks are some of the best to build in. For example, the Gardners’ treehouse was built in a group of trees. It includes oaks and poplars.

Once a site has been selected, McDonald sketches out a rough drawing of what a client’s treehouse might look like. He considers the best locations for windows and outdoor balconies so owners can have the most spectacular views. The Gardners’ treehouse is positioned so the family can look out over their farm and stables, where they keep horses, goats, and donkeys.

In addition to using hand-drawn illustrations, the Nelson team uses drones to help plan designs. These small robotic aircraft fly around the trees taking hundreds of digital photos. Computer software converts the images into a virtual 3-D model. Designers use the model to make precise measurements of the trees. “That allows us to accurately design and construct a lot of the structure off-site,” explains McDonald.

After McDonald picks a site, he makes a rough drawing. It shows what the customer’s treehouse might look like. He thinks of the best spots for windows and outdoor balconies, to give owners the most amazing views. The Gardners’ treehouse is placed so the family can look out over their farm and stables. That’s where they keep horses, goats, and donkeys.

The Nelson team doesn’t only make drawings by hand. They also use drones to help plan treehouses. These small robotic aircraft fly around the trees and take hundreds of digital photos. Computer software turns the photos into a virtual 3-D model. Designers use the model to make exact measurements of the trees. “That allows us to accurately design and construct a lot of the structure off-site,” explains McDonald.

After enough information about the Gardners’ site was collected, the team drafted a blueprint of the treehouse back at their Washington headquarters. Then it was time to build.

The team collected enough information about the Gardners’ site. Then they made a blueprint of the treehouse back at their Washington headquarters. It was time to build. 

The first step in constructing the Gardners’ treehouse was to make its platform—the flat ground floor that’s connected to the trees. Solid steel bolts, called treehouse attachment bolts (TABs), anchor the platform to the trees. McDonald explains that TABs are the treehouse’s backbone. They also stabilize the structure so it’s not damaged by rough weather.

The team got started on the Gardners’ treehouse. The first step was to make its platform. That’s the flat ground floor that’s connected to the trees. Solid steel bolts hold the platform to the trees. They’re called treehouse attachment bolts (TABs). McDonald explains that TABs are the treehouse’s backbone. They also steady the structure so rough weather doesn’t harm it. 

Each TAB is inserted into holes drilled deep into a tree trunk and can support up to 4,500 kilograms (10,000 pounds). Mature trees grow only from the tops of their trunks. Since TABs are placed at lower or middle regions of trunks, the treehouse remains level over time. McDonald explains that the TABs don’t harm a tree. Instead, a trunk eventually grows strong fibers under where the TAB is inserted. That helps to further support the load of the treehouse. “The tree treats a TAB like a branch. Branches naturally have a stronger, tighter grain on their underside to support the weight of the limb,” says McDonald.

Holes are drilled deep into a tree trunk. Each TAB is placed inside a hole and can hold up to 4,500 kilograms (10,000 pounds). Older trees grow only from the tops of their trunks. TABs are placed at lower or middle areas of trunks. That way, the treehouse stays level as the trees grow. McDonald explains that the TABs don’t harm a tree. Over time, a trunk grows strong fibers under each TAB. That helps to support the load of the treehouse even more. “The tree treats a TAB like a branch. Branches naturally have a stronger, tighter grain on their underside to support the weight of the limb,” says McDonald. 

Once the platform is complete, workers truck in walls and other parts built off-site. The crew installs the pieces and covers the structure’s exterior in western red cedar siding. This wood is naturally resistant to rot thanks to chemicals called tannins. Electrical lines, plumbing, and connections for heat and air-conditioning can be run into the treehouse. The Gardners even had an outhouse with a toilet installed.

It takes the crew about three weeks to complete construction—and that’s when the real fun begins. “My favorite thing to do is to have my friends over to the treehouse,” says Anna. “We have a great time spending the night and having a sleepover.”

Walls and other parts are built off-site. The Nelson crew trucks them in when the platform is finished. Then workers put the pieces in place. They cover the outside of the treehouse in western red cedar siding. This wood has chemicals called tannins that protect it from rot. Workers run electrical lines, plumbing, and connections for heat and air-conditioning into the treehouse. They even built an outhouse with a toilet.

The crew takes about three weeks to finish building. That’s when the real fun begins. “My favorite thing to do is to have my friends over to the treehouse,” says Anna. “We have a great time spending the night and having a sleepover.”