About the Spheres

We Are the Original Manufacturer of Spherical Treehouses


We build spherical treehouses as works of art – functional, tasteful, simple, and elegant. We invite people to come and spend a night or more in our unique and magical forest hotel. Free Spirit Spheres is the first and only manufacturer of spherical treehouses in the world.


Design, Construction and Rigging

Much of how we design and build at Free Spirit Spheres is informed by the principle and practice or Biomimicry. According to the Biomimicry Institute (biomimicry.org): “Biomimicry is an approach to innovation that seeks sustainable solutions to human challenges by emulating nature’s time-tested patterns and strategies. The goal is to create products, processes, and policies – new ways of living – that are well-adapted to life on earth over the long haul.”

Externally the spherical nut shape is certainly well adapted to life in the forest. A sphere distributes any impact stress throughout the skin and resists puncture or cracking. Like a ping pong ball or a nut, it’s light with a tough skin. The suspension ropes which stretch also absorb some of the force. The suspension concept also reflects biomimicry. The network or web of ropes used to tether the sphere vertically and laterally function much like a spider web – a very strong and resilient distributed structure indeed.

A suspended sphere is tethered by 3 nearly vertical ropes to strong points on each of 3 separate trees. This distributes the load evenly over the 3 trees and results in a stable hang. Like an inverted three-legged stool, there will be almost equal tension in each of the three suspension ropes. The sphere resides in the center of the triangle formed by the 3 trees. It can be slung from 5 to 100′ off the ground, depending on the size of the trees. A tree house sphere uses the forest for its foundation. The occupants have a vested interest in the health of the grove. The supporting web also mirrors our connectedness to our eco-system.


The spherical treehouse concept also borrows heavily from sailboat construction and rigging practice. It’s a marriage of tree house and sailboat technology. Wooden spheres are built much like a cedar strip canoe or kayak. Suspension points are similar to the chain plate attachments on a sailboat. Stairways hang from a tree much like a sailboat shroud hangs from the mast. Spherical architecture has many unconventional features. Conventional buildings separate walls, ceiling and floor with hard lines. In a sphere the walls and ceiling merge into one. The function changes but the form remains the same. It is a unified structure with one continuous wall. I call this uniwall construction. There are only 2 sides to a sphere – inside and outside.

Each sphere has four attachments on top and another four anchor points on the bottom. Each attachment is strong enough to carry the entire sphere and contents. A sphere is accessed by a spiral stairway and/or a raised walkway which connects to a landing platform and a short suspension bridge. The two lower back suspension points of the sphere are tied horizontally to the two back trees, preventing the suspension bridge from sagging when it is walked on. The door faces the “door tree” and the suspension bridge connects the two via a customized platform.

The first two spheres were made of wood – Eve of yellow cedar with a diameter of 2.8 m, and Eryn of sitka spruce, with a diameter of 3.2 m. From the larger sphere Eryn, we made a mold, which gave us the capability to make fiberglass “shells” that are exactly the same size as Eryn. Whereas it took over 2000 hours to make Eryn’s hull, with the mold we can make a fiberglass sphere in under 200 hours!


On the interior side is where we really focus on our mantra of “functional, tasteful, simple and elegant”. Both wooden and fiberglass spheres are insulated with multiple layers of reflective bubble wrap. Vinyl upholstery fabric is stapled to the frames, which are offset at 20 degree increments and connect the north and south poles. Each fabric joint is then covered with a decorative wood strip. The wood strips come together at the top and give a nice cathedral ceiling effect. The joinery style is borrowed from yachts, using brass trim, varnished wood and cane doors. They have closets on either side of the door. These function as partial bulkheads to reinforce the door opening as well as adding cupboard space.

We have experimented with both static and movable bed and table layouts. In Eve and Eryn there is a bed under one large window and a settee table under the opposite window. The Eryn model also features a loft bed that is integrated with circular shelf segments connecting the loft bed to the cupboards on either side of the door. The back wall opposite the door provides a galley area with counter cupboards and a sink. More detailed photos of Eryn’s interior can be viewed on the All About Eryn page.

Melody, our first finished fiberglass sphere, reflects more of an open concept, with integrated cushioned benches under both large windows. There is a small galley area with a sink to the right of the doorway, and a closet with slide-out shelves on the left hand side. On the wall facing the door, two matching tables fold up and down as desired. When the tables are folded up into the wall, the whole wall is pulled down as a Murphy bed. More detailed photos of Melody’s interior can be viewed on the All About Melody page.


What’s New?

Check out our Blog and Recent News for the latest ….

Recent News