Canada's Passage Island: A Shell Structure Retreat

Canada's Passage Island retreat: Building Canada's first shell structure on a tiny island off Vancouver, British Columbia, including pictures, floor plan and walking through the construction process.

| September/October 1988

Canada's Passage Island retreat: Building Canada's first shell structure on a tiny island off Vancouver, BC. 

Passage Island Shell Structure Retreat

IT WAS 1968 AND MY WORLD WAS falling apart. In the first three months, I buried my mother, my best friend and a shooting buddy. In June, I was divorced after 26 years of wedded "bliss." The Vancouver, British Columbia, metropolitan rat race was getting me down, and I wanted out. Then I found Passage Island. Passage Island—what a tonic. As virgin as when the world began. Unsullied by people, pesticides or pollution. The primitive openness and flexibility of life there was a welcome contrast to the urban, fixed-class society I was accustomed to.

Guarding the entrance to Howe Sound, Passage Island is insulated from downtown Vancouver's big city woes by eight miles of salt water. No utilities, no garbage trucks, no telephones, no fire stations, no policemen, no industry—just 32 acres of beautiful British Columbia. I escaped to that paradise for a few hours each week to move rocks, saw logs, watch the tide come in and go out—all in the name of therapeutic basket weaving. It was like having my own personal psychiatrist. I loved it. I loved it so much that I bought it.

I knew that, subdivided into one-third-acre waterfront lots, Passage Island was sure to attract a stream of spiritual refugees—refugees, like me, from the rat race. Back then, one of the waterfront lots would bring $6,200, which would help recoup my investment. In short order, the decision was made. In less than six months my life had turned around. I would build a house on Passage Island, move there and start anew. But not just an ordinary house. During 15 years in the construction business, I'd built quite a few of those. This had to be something different, something unique, something with a kind of permanence that had so far eluded my world. I'd long enjoyed working with stone, concrete and tile. And a fireproof house on an island with no fire department made good sense. So masonry was the building material of choice.

As for design, I considered and discarded many before remembering a structure I'd seen in Mexico, two years before. In a suburb of Guadalajara, I'd come upon this incredible building, still under construction. The formwork had just been removed from a spectacular, self-supporting, very thin concrete roof. It rose from four corner footings in graceful parabolic arches, forming four vaults that were groined together.

I'd heard of shell structures—more properly called hyperbolic paraboloids—but I'd never seen one. The concrete was a mere 1-1/2 inches thick, with only tiny 1/4-inch rebar spaced four inches each way for reinforcement. Yet this fragile-looking roof provided a clear span of 90 feet. The structure gained its strength from its elegant shape—a paradoxical double curvature that can be described (and formed) entirely by straight lines. Concrete technology of this caliber was simply nonexistent in Canada.

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