This treehouse sauna is an amazing hideaway—“The sauna feels like its own little world”

What inspired you to build a treehouse sauna?

I came up with the idea on a whim and out of necessity. We didn’t have a sauna, and I used to be an avid sauna-goer. As a child, I was also fascinated by treehouses. Our garden had old, large pine trees in just the right spots, and the pines also offered a wonderful view over the fields.

Can you tell us about the planning and construction of the treehouse sauna? What was the most challenging part, and were there any surprises along the way?

It was a success. The sauna looks exactly as I envisioned it to look. The planning started with the trees: I first sketched the sauna on paper, then consulted a friend who works as master builder. Together we did the load-bearing calculations. The pine trees determined the size, as the sauna had to fit between them.

Initially, the idea was to build a log sauna, but I decided to construct it from two-by-fours instead. When you keep things simple, they’re easier to implement. We started building in the spring, and the sauna was completed in the autumn of 2019. We built it on the ground and lifted it up fully assembled.

The treehouse sauna is built from two-by-fours. The whole structure weighs about four tons.

The sauna is heated with a wood-burning stove, and there’s no electricity or running water up there. The treehouse sauna is a device-free zone.

Apart from the dressing room, I treated the sauna’s exterior and interior surfaces by charring them with a gas flame, which was new to me. At times, I wondered if the whole sauna would burn down. Charring is an old Japanese technique that’s rarely seen here. After charring, the surfaces were treated with a mixture of tung and linseed oil.

Perhaps the most difficult aspect, or at least something that wasn’t familiar to me from regular construction, was attaching the cable bolts to the trees. I had to hit the right spot on the first try.

How is the sauna attached to the trees?

The sauna rests on two thick glulam beams and four bolts attached to the trees, along with cables. The bolts allow for some movement, preserving the living structure so the trees can continue to live and grow normally. The attachment model is based on the Garnier Limb technique I found online, which is used worldwide in treehouse construction.

For the bravest sauna goers, there’s a hammock for cooling off on one side of the sauna.

The sauna has a floor area of 12 square meters, divided almost equally between the sauna and the dressing room.

In the dressing room, you can gaze even higher into the sky through the skylight.

The sauna can accommodate about eight people at a time.

What have people said about your treehouse sauna?

People often ask if it was difficult to get a building permit. I don’t want to brag, but there were no problems in getting the variance permit. Many also admire how a sauna built from two-by-fours can look so good. Charring the surface gave it a nice, lively, slightly scaly appearance, which has also weathered well thanks to oiling.

What’s it like to take a sauna three meters up in the trees?

The atmosphere is completely unique, as the sauna feels like its own little world. Even the soundscape is a bit different up there. We spend at least a couple of hours sitting on the sauna benches and cooling off. It’s nice to watch the scenery and see deer and foxes in the fields from the sauna. When there’s a strong wind, you might feel a slight sway.

The sauna’s railings are made from pine branches.

The surfaces of the sauna were charred with a gas flame and oiled.