Exterior walls for operations buildings prioritize transparency

As walls are installed at the north and south portal operations buildings in the coming weeks, drivers may be surprised by how little their view inside the buildings changes. The exterior walls of the large fan rooms will be made of glass, providing passersby with a glimpse of the everyday activities that will occur inside these important operation centers.

The decision to use glass walls arose out of the guiding principles for the operations buildings: to reflect their function and contribute to the quality and fabric of their districts. The guidelines for the two buildings were developed by WSDOT and their architect NBBJ in conjunction with the Seattle Design Commission in 2010. 

The structures’ glass walls will portray the purpose and function of these nerve centers. Travelers will be able to glance inside as they enter the tunnel at both ends, and pedestrians will enjoy special viewing areas along the plazas that will surround both buildings.  

The structures are designed to fit well in their new neighborhoods. In the south, the operations building will be well integrated along one of the city’s primary industrial corridors. In the north, the structure will echo the gated Seattle City Light substation a few blocks west.

Designers envisioned that these buildings would act as beacons of light rather than blocks of cold concrete. The ventilation rooms of both operations buildings will stay lit throughout the night, acting as luminous bookends to the bored tunnel.

Keep an eye on the operations buildings as you pass by in the coming weeks: the glass walls may be difficult to see, but the purpose of the buildings should be pretty clear. 

The view from inside the south portal operations building, looking southeast toward the stadiums. Glass walls will be installed in the coming weeks.


A rendering of the south portal operations building.