The full façade of this historic, unreinforced masonry Seattle Plumbing Supply building built in 1903 was preserved. The 11-story concrete and steel building contains a mix of condominiums, parking, and at-grade retail and restaurant space. Above the façade, residential units reach story heights close to 20 feet.Amenities include a large indoor clubroom with a gourmet kitchen, fireplace, and a wine nook, as well as an outdoor terrace with full views of downtown, the port, mountain, and beyond.
Preservation of the façade was closely integrated with new construction. A custom designed strong-back support system reinforced the façade during construction. Tying historic elements to the new structure increased their seismic stability.
Openings in the post-tensioned slabs incorporated the facade support frame, then closed as the framing was removed, facilitating efficient construction sequencing.
Worked closely with the geotechnical engineer in the selection of the appropriate foundation system, which was built over reclaimed tidelands and soft soils. The team selected a mix of pin pile and augercast pile foundations that were integrated into the temporary shoring and permanent foundation system, saving time and money for the owner.
Included planning for a future pedestrian plaza, park, and significant roadway realignment. Design element coordination included detailed grading in the future plaza to match the project grades.
Early collaboration with Waterfront Seattle decision makers and planners resulted in positive decisions for Gridiron’s developer and beneficial, thoughtful planning for the future community park.
