Silman provided structural engineering services for this new glass home, featuring twelve foot tall thermally insulated glass doors, continuous clerestories, and large two-way cantilevered roof, borrowing volume and energy from its natural surroundings. Through the innovative collaboration of skilled project team, this private residence in East Aurora, NY achieved an ecologically sensible, material and energy efficient design while remaining under budget.
The thin roof structure floats above the glass walls as a double cantilever, eight feet toward the pond and twelve feet toward the dense forest. Within this slim dimension exists tapered insulation, roof sheathing, closed cell foam, operable shading devices, a low-velocity return air plenum, recessed high-efficiency lighting, and ceiling finishes – ultimately, very little room for structure. As a result, the framing utilizes a precise blend of engineered wood framing coupled with flush-framed structural steel.
As challenging as the roof structure was, the innovation and optimization of the slender column elements pushed the limits of design. From tip to base, the columns are approximately 13 feet tall without bracing, yet their section is limited to 2” x 4”. To accomplish this extreme slenderness, the column bases were rigidly fixed to the frost wall below and later encapsulated by the finished concrete floor. The column tip was rigidly welded to the underside of a compact wide flange section which also serves as the spandrel support for the roof. The result is a reduced K-factor and a column which fits within the aluminum enclosure provided by the operable door manufacturer.
The lateral system posed its own challenges. Due to the slenderness of the gravity columns and the appearance of continuous roof support by glass, rigidly connected steel frames were embedded within the aluminum clerestory to resist in-plane lateral loads. The result is a lateral stiffness sufficient to maintain the proper function of the tall, operable glass doors.