A tight budget, a rural location on the cliffs above the Columbia River Gorge and a jobsite attached to a 100-year-old museum listed on the National Register of Historic Places combined to challenge designers and contractors on a 25,500-sq-ft expansion of the Maryhill Museum of Art in Goldendale, Wash.
GDB Architects and contractor Schommer & Sons, both of Portland, teamed up to deliver a $9.5-million expansion of the 1914 museum. The addition had to fit with the historic character while minimizing visual impact on the 5,500-acre site tucked into the cliffs.
Only 8,425 sq ft of the modern steel-and-glass structure is visible above ground. To create the rest of the space, designers went underground. Dynamite was deemed too risky near the aging original structure, so crews used excavators to chip away 16,000 cu yd of fractured basalt.
Using cast-in-place concrete, the team cantilevered the underground portion of the construction away from the cliff nearly 20 ft, providing views never before available from the building. Schommer & Sons self-performed all concrete work.
"The cantilevered deck turned out great," says Paul Schommer, project manager with Schommer & Sons. "One of the highlights of the design was to take advantage of the extensive views. [The addition] being cast-in-place [concrete], in my opinion, integrates it into the building a little better."
Three beams running 53 ft underneath the new building provide its structural anchors. Shoring was removed only after steel erection was complete to help counterbalance the cantilever over the hillside.
In a project designed to achieve at least LEED Gold certification, Schommer says the team ground up all on-site basalt that was pulled out of the pit, re-using it as gravel base layers for new construction and access roads. Additional sustainability was achieved by using water from on-site springs as a heat exchange. The 52°-F water can help heat or cool the building as needed. Nearly 38% of the materials are local or regional in origin.
Maryhill Museum of Art Expansion and Renovation, Goldendale, Wash.
General Contractor: Schommer & Sons Inc., Portland, Ore.