NAC|Architecture addition

Location: Spokane

Owner/developer: NAC|Architecture

Project team: Kearsley Construction, general and concrete contractor; NAC|Architecture, architect; Spokane Rock Products, ready-mix supplier

NAC|Architecture’s new three-story office addition in Spokane is a cantilevered glass studio that extends over a stone wall base with a cast-in-place concrete stair tower anchoring the corner.

The 10,000-square-foot addition, which adjoins the firm’s original historic brick building, expands the studio, administrative and support space. The small infill site was previously a nine-car surface parking lot.

The compressed floor-to-floor heights of the original masonry building drove the design team to pursue a post-tensioned concrete structure with the shallowest possible structural depth, with no exterior columns and limited interior columns in the studio spaces.

Seven-inch concrete floor slabs with 7-inch dropped concrete beams are the predominant interior finish in the building. The ceiling structure is exposed unfinished concrete with additional acoustical material applied to better serve the office environment.

Major circulation areas utilized a grinding and polishing process to highlight the concrete floor structure as the floor finish. The cast-in-place concrete stair structure is exposed to both the exterior and the interior studios. The post-tensioned roof slab easily accommodated large bays of skylights, maximizing the third-floor interior daylighting.

The project earned a LEED silver rating. Points were awarded for daylighting, high recycled content and low-emitting materials, including concrete finishes. The structure supports a small green roof demonstration area where clients can see first hand how the system looks and performs.