Owner: Seattle City Light
Contractor: Walsh Group
Lead Designer: POWER Engineers Inc.
Structural Engineer/Civil Engineer: KPFF Consulting Engineers Inc.
MEP Engineer: Notkin Mechanical Engineers
Architect: NBBJ
Landscape Architect: HBB Landscape Architecture

Denny Substation doesn’t look like what you’d expect from a structure of its kind. That’s by design, due to its setting within South Lake Union, a growing area of Seattle. A 120,000-sq-ft area for an open-air insulated power substation, for example, was out of the question. One option—an underground substation with a park above—was too expensive. 

The team could have gone with a more typical design, but “rather than making this kind of an unsightly thing [with] a nasty chain-link fence with barbed wire on top, we wanted it to be more of an attraction,” says Jay Keeling, consultant team program manager with POWER Engineers, the lead engineer.

After an extensive public input process, the end result is a low-profile structure with architectural screening walls that angle inward, along with 44,000 sq ft of open space including a dog park and elevated walkway. The path was based on natural walking patterns in the space, determined from a foot traffic study. Pedestrians can look through the 4-in.-thick bulletproof glass revealing the “compact design” of the inner workings, including the closely spaced gas-insulated conductors.

With the Seattle Cancer Care Alliance as a neighbor, “of course there was a big fear of [electromagnetic fields]. In our design we eliminated almost all EMF,” says Keeling. An outside analysis “confirmed that it was at or near zero in all the public spaces. Even within the site it’s really low. Far lower than usual.”

Sustainable design elements include a 40-kw solar photovoltaic system, heat recovery, planting of drought-tolerant native species and retention basins for stormwater runoff.

The project came in over budget, due in part to the owner Seattle City Light’s decision to conduct an environmental impact statement to be proactive in dealing with community concerns.

Back to ENR's Best of the Best Projects 2019