“We decided to create an environment that appeared to be alive and growing,” says Farrow, a senior partner at Farrow Partnership Architects. He made a few sketches and foamcore models for the 11,500-square-foot space before creating a triangular floor plan centered on four sprawling columns comprising Douglas fir glulam (glue-laminated) members.

The massive engineered timbers curve 44 feet 6 inches up to the beams that support the atrium roof. Like trees, the structural columns sprout almost seamlessly into glulam branches that further support the roof frame.

Tree 3

Designed in 2003, the project precedes today’s advanced 3D modeling software and fabrication technologies. Early in the design process, Farrow and his team began a steady dialogue with manufacturing and installation partner Timber Systems Limited, based in Markham, Ontario, to detail the complex geometry. Timber Systems modeled and mapped hundreds of joints using Dietrich’s 3D-CAD/CAM software for wood construction.

Tree 4

Even with a tight budget, Gary Williams and Tye Farrow developed an innovative system to conceal the connection plates. Instead of two exposed plates, they inserted a single, 3/8-inch steel plate into a slot mortised into the center of each glulam member.

Credit: Timber Systems

The original drawings called for external steel connectors. But Timber Systems president Gary Williams felt that the metal would disrupt the aesthetic—“Trees,” he notes, “don’t have sideplates”—so the Timber Systems team spent hours devising a system of concealed connectors.

Tree 5

Farrow says the cancer center had the most intricate wood structure in North America when it opened in 2004. Ten years later, Williams says there has been no need for any maintenance or refinishing of glulam components. This May, Farrow dropped by to judge for himself. “It looks as good as it did when it opened,” the architect says. “Maybe even better, thanks to the patina it has picked up.” Even now, Farrow still hears from patients and their families, who call the space “uplifting” and “natural.”

A Geoffrey James photograph of a tree in Prospect Park, in New York, served as Farrow’s early design inspiration. “Trees symbolize strength and comfort,” Farrow says. Because the unconventional design looked astronomically expensive, the project’s funder, the Ontario Ministry of Health and Long-Term Care, required a cost analysis during the final design phase. Farrow’s concept proved less expensive than standard steel construction, prompting one hospital board member to call the design “beauty on a budget.”

Tree 6

The glulam timbers total more than 25,000 cubic feet of Douglas fir, the equivalent of 60,000 residential studs. Six different jig settings were used to construct the glulam arches.

Though the reduced amount of steel helped offset the additional design costs, the timber system still required more than 60,000 pounds of steel brackets and rods. The plates were predrilled with holes that aligned with predrilled holes in the glulam faces. One-inch-diameter steel rods, ranging in length from 4-5/16 inches to 10-13/16 inches, were hammered into the holes, which were then plugged with wood. Though CAD software was essential for designing the complicated system, Timber Systems had no CNC cutting machines in 2004. Instead, workers mortised the slots and mitered the ends manually, using a bench-mounted chainsaw in the factory.

Note: This article has been updated since first publication to clarify the full name of Timber Systems Limited and its location in Markham, Ontario.