CornerStone

Celebrating Seattle’s timber origins with a mass-timber framework, the 182,000 GSF CornerStone illustrates what an ecologically-minded neighborhood scale office can be.

Form frames function with a design that captures rainwater utilizing sloping shed roofs, while strategic carvings from the facade allow natural daylight to penetrate deep into the building. An exposed DLT floor system and glulam structural frame anchor the 3-story mass timber over a 2-story podium concrete structure with subgrade parking. With a forward-looking biophilic design, CornerStone highlights the benefits of natural wood materials and patterns, access to views, fresh air, and ample daylighting.

At the entry, a honeycomb-inspired Alaskan cedar pergola references a rooftop bee apiary, drawing the eye upwards to highlight the regionally sourced mass timber structure. One of the first uses of DLT in Seattle, CornerStone’s timber structure saves 1,886 metric tons of CO2e, reducing the building’s carbon footprint by 35%.

CornerStone achieved Petal Certification from ILFI’s Living Building Challenge, including the arduous Materials Petal. With more than 1,000 materials vetted for the avoidance of toxic chemicals, Cornerstone prioritizes indoor air quality for tenants while educating the public about material transparency and health. DLT utilization meant not only a more beneficial timber grid, but also reduced off-gassing, given a much lower adhesive volume used in the panels.

With a challenging water reduction target to eliminate usage of all potable water for non-potable uses, the design team needed to maximize roof area to capture as much rainwater as possible, directing it to a massive 268,745-gallon below grade cistern. Balancing roof area with equally important daylighting needs to reduce energy usage by 30% led to the dramatic east-facing façade design. Massive timber braces support a large roof overhang shading expansive floor-to-ceiling glazing while showcasing the strength and beauty of the timber structure.

The combination of these design decisions creates a building that not only supports tenants' health and wellbeing, but also shares its timber story with the surrounding community.