Architect Warren Schwartz, FAIA, credits a sunrise visit to the rim of the Grand Canyon—and a later dream about the experience—as the seed for the Berkshire mountains summer house he shares with his wife, violinist Sheila Fiekowsky. Schwartz, who is in the habit of doodling while his wife fiddles, worked out the basic concept during Boston Symphony Orchestra concerts. “I just drew the memory of this dream while I was at Symphony Hall,” he recalls. At one intermission, he ran into structural engineer Sarkis Zerounian and handed him a concert program covered with elevation sketches. At the end of the concert, Zerounian handed back a preliminary structural design.

The result of this classically scored collaboration is a slender chevron, clad in glass and anodized aluminum, that follows the sloping grade for half of its length before leaping into a gravity-defying 45-foot cantilever. A massive concrete foundation under the earth-bound half anchors the cantilever, effectively acting as a bridge abutment. “But here,” Schwartz notes, “we have only half a bridge.” Steel-framed floor and roof decks and steel-tube members form a three-dimensional truss, in which the floor actually hangs from the roof.

In plan, the building is surprisingly down-to-earth. “I always use the analogy of a Pullman car,” Schwartz says. “The rooms are on the right, and the corridor is on the left.” The corridor descends three sets of folded-steel stairs, passing three bedrooms and a separate staircase to the roof deck, each of which occupies its own concrete landing. The elevated entry provides a preview of the vista that wraps the airborne great room.

Builder Chris May’s background in commercial construction prepared him well for the construction methods involved—with its steel frame, glass curtain walls, and concrete topping slabs, the building contains virtually no wood—but in the essential matter of how the building would hold itself up, he simply had to trust the engineer. And Zerounian delivered. “He told us how much out of level to hold that cantilever up,” May says, and when the crew removed the temporary screw jacks under it, the structure settled exactly as predicted. “I don’t think the floor is more than 1/8-inch out of level in the 40 or 50 feet it cantilevers out there. It was like cooking a soufflé that comes out perfect: You don’t know what you did, but it worked.”

Schwartz and Fiekowski’s commitment to the design also required a leap of faith. But the house, their home base during the BSO’s summer seasons in Tanglewood, Mass., lives up to the dream that inspired it. Descending through the building, toward a mountain-and-valley view that stretches into New York state, one’s elevation above grade actually rises. Visitors liken the sensation to a ride on a biplane or a magic carpet. “You feel like you’re in a high-rise building,” Schwartz says. “It’s a horizontal building that feels vertical.”

architect: Schwartz/Silver Architects, Boston

builder: Chris May Builders, Richmond, Mass.structural engineer: Sarkis Zerounian & Associates, Newton, Mass.

photography: Alan Karchmer /Sandra Benedum

resources: bathroom fittings/fixtures: Duravit; dishwasher: Bosch; entry door, patio doors, and windows: R&R Window Contractors; exterior siding: McNichols; hardware: Sargent Manufacturing; hvac equipment: Trane; kitchen cabinets: IKEA; kitchen plumbing fixtures: KWC America; oven: Dacor; range: Bosch; refrigerator: Liebherr; roofing: Sika Sarnafil

A version of this article first appeared in CUSTOM HOME magazine.