Owner: Mack Urban
Lead Design Firm: Ankrom Moisan Architects Inc.
General Contractor: Exxel Pacific Inc.
Civil/Structural Engineer: Coughlin Porter Lundeen Inc.
MEP Engineer: Rushing Co.
Like its namesake passenger ferry that operated on Puget Sound well over a century ago, the Cyrene apartment building runs on steam.
The Seattle Steam Plant adjacent to the 16-story, 212,174-sq-ft building on the city’s waterfront provides an energy-efficient power source for heating and cooling Cyrene’s 169 units.
Created from groundwater sources, the plant’s steam travels only 15 ft through basement walls to Cyrene’s heat exchanger, says Jesse Keely, senior project manager with general contractor Exxel Pacific Inc.
Condensate water from the heat exchanger then returns to the steam plant for reuse.
“They’re not very complicated machines—in fact, the technology is quite old,” Keely says. “They are very efficient, with very few moving pieces.”
To build the $48.2-million project, the team needed to address contaminated soils—mostly burn debris from the historic Seattle Fire of 1889. Early cores found pockets of lead-contaminated soil, which were excavated and loaded directly into a lined container for shipping to a disposal site out of state.
“The site used to be a big dock,” Keely says. “The water line was back farther then. The railroad ran right by there—they dumped their garbage there. Some of the lead was from old batteries that they had in the lamps.”
The waterfront site had to be dewatered. This included treating contaminated groundwater using baker tanks and filtration systems. Crews, which placed 80-89 foundation piles, also arranged to protect the site from groundwater.
“We had provisions in place for a significant amount of groundwater—a big cofferdam in the core of the building,” Keely says. “But the water wasn’t there.” That was thanks to a seawall under construction nearby, which had blocked much of the groundwater.
Tides added another element of uncertainty. On rainy days at high tide, water flooded the site, while on other days, workers had to truck in water to facilitate drilling.
Subcontractors had to avoid existing electrical, fiber-optic and steam utilities. And Exxel had to coordinate construction with a city gas-piping replacement project.
As a nod to the past and future, Cyrene’s accent facade panels waft up the side of the apartment house like steam rising from a stack. In the end, the steam plant, which was first thought to be the site’s greatest liability, turned out to be the project’s biggest asset, says the team.
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