The Mark at 5th & Columbia Project


The Conco Companies is providing concrete services for The Mark, a 48-story high-rise tower in Seattle, WA that will consist of 528,000 sq. ft. of Class A+ office space, as well as a luxurious 189-room SLS hotel and spa. Conveniently located in the city’s central business district, the stunning beautifully designed tower will incorporate a wide range of “green” building features such as rain water management, photovoltaic glass and light pollution reduction. Scheduled for completion in April, 2017, the tower will bring to the area first-class office space that is highly divisible and offers 9’ 6” windows for natural light and spectacular views.

Concrete Pumping - The Mark

The 5,000 cubic yard mat foundation pour was completed in June, 2015 and required approximately 500 truckloads of concrete over the course of the day. The project also includes a sub-level parking structure comprised of shotcrete perimeter walls and a concrete elevator core. As of May 2016, Levels 5-11 decks have been poured and the core poured to Level 35. When the elevator core reaches Level 35, the remainder of the building steel will be erected in one continuous phase.

The building’s unique geometric facade provides exterior seismic bracing for structural safety as well as column-free floor plates. Unobstructed by columns or bracing, the 13’ 6” floor-to-floor heights will allow for individualized, open plans or heavy build-outs. The Mark is seeking LEED Gold Certification.  

The SLS hotel will be a collaborative effort from the Founder and CEO Sam Nazarian, renowned designer Philippe Starck, and chef James Beard. The hotel will also include 15,000 sq. ft. of meeting space, a 5,000 sq. ft. ballroom, sky lounge and two restaurants. Adjacent to the SLS Hotel are two historic buildings. A century-old sanctuary building, the First United Methodist Church, and the Rainier Club. Founded in 1888, the Rainer Club has occupied their current building since 1904.

Additional information is available at

The Conco Companies - The Mark
5th & Columbia Washington Concrete

The Conco Companies is one of the foremost suppliers of concrete services for the Western U.S. We began operations in 1959 in the Bay Area by offering clients the best value on a broad range of concrete services and products. Since that time, we have taken a leading role as top concrete contractors in the region. We have four regional offices serving California, Oregon, Nevada, Colorado and Washington.

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