Longitudinal sitka-spruce stringers - the sphere builder's equivalent of wall studs - are fastened to the interior skin with epoxy.

Spherical buildings present some obvious practical challenges. But because a sphere provides the largest possible interior volume per unit of surface area, the form has long fascinated designers and architects, and quite a few reasonably successful spherical structures have actually been built. Most - like the geodesic domes pioneered by Buckminster Fuller in the mid-20th century - simply approximate a spherical shape with a network of flat triangles. But Canadian builder Tom Chundleigh has chosen to take the high road: The guest cabins at his Vancouver Island, British Columbia, eco-resort are true, geometrically perfect spheres.A circular plywood floor prevents the...