Home AEC Seattle Review Board Requests Two-Tower Mercer Blocks Project Return for Second Recommendation...

Seattle Review Board Requests Two-Tower Mercer Blocks Project Return for Second Recommendation Meeting

Alexandria Real Estate, NBBJ, Mercer Blocks, Seattle, South Lake Union
Courtesy of NBBJ

By Bekka Wiedenmeyer

Seattle’s South Lake Union neighborhood was built on the back of industry. Populated with warehouses and industrial buildings, the area was home to David Denny’s Western Mill, Boeing’s airplane plant and the Model T factory. It wasn’t until the late 1990s when the character of South Lake Union shifted to a contemporary model, with multistoried office buildings and residential towers cropping up to repurpose the density. Warehouses turned into commercial buildings, and street-level activation allowed for human activity while encouraging tower development. With this idea in mind, Seattle-based real estate company Alexandria and architecture firm NBBJ joined together to present a revised proposal for the Mercer Blocks Project to the West Design Review Board in mid-June. At the conclusion of the meeting, the Board voted to return the two 13-story structures for a second recommendation meeting in response to the guidance provided.

The site, located at 816 Mercer Street and 714 W Mercer Street, is currently vacant and occupies an entire block within the South Lake Union Urban Center. A vacant lot, a warehouse structure and city landmark Puget Sound Power and Light Co. Utilities Building are located north of the site across Roy Street. To the east is a life sciences building across 9th Avenue N., with another life sciences building and a vacant lot located to the south across Mercer Street. The project site is placed at a gateway location between the civic performing arts venues in Lower Queen Anne, the Seattle Center campus and the science and research facilities in South Lake Union. The neighborhood itself is characterized by mixed-use and multi-family residential buildings, as well as office, research, commercial, hospitality and education structures. 

According to project documents, the proposed development consists of two 13-story structures which will stand at 485,600 square feet and 379,126 square feet, respectively. The west building will house a 30,000 square foot recreation center with a sport court and childcare, with a tenant meeting space and retail spaces in the east building. Three-and-a-half levels of below grade parking will be provided, with approximately 600 stalls for use.

The project goal is to create net positive health and increase awareness on how to improve lives. Through exposure to context, sustainability, legacy and innovation, the team hopes to engage the public and stitch the Lake Union community together with the city of Seattle as a whole.

During the meeting, the applicant presented the approved massing option from early design guidance (EDG). “Slow Cut” divides the tower masses diagonally across the block, pushing the feeling of movement from prevailing watersheds and Old Broad Street. The lifted podium along the slow cut emphasizes the recreation center and ground floor elements, expanding the public area three-dimensionally, and pavilions have a separate identity from the rest of the project. Varied scale and mass along edges and corners create a distinction between the buildings. The west building has a large raised podium and cantilever to give massing prominence to the Recreation Center. The east building is scaled horizontally and has three distinct levels, which respond to the larger context. Building masses are reduced significantly along the slow cut to increase the size and experience of the public realm along 8th Avenue. While the massing concepts of each building are distinct, they support the overall vision of the “Slow Cut” approach.

During the recommendation meeting, the Board voiced their appreciation for how well the design had developed since EDG, and for the emphasis of the massing scheme as it related to programming and context. They were concerned, however, that the design concept had diminished in strength since the previous iteration, noting that the project should be revised to clarify and re-emphasize the “Slow Cut” approach, particularly as it relates to the lifted podium. The Board continued to support the massing approach but had concerns regarding its legibility from the pedestrian area. The Board encouraged the team to continue refining the exterior expression of the east building, which according to the meeting report had a “weak execution of the clerestory-inspired fenestration.” The Board also recommended the team continue to explore ways to better meet design guidelines for avoiding campus-like character in large projects by making the two buildings more similar in architectural character, while emphasizing the different expressions of public elements.

The Board was supportive of the Recreation Center’s distinct expression, however, they encouraged the team to continue refining the design to differentiate it from the office towers. They also recommended the team explore better ways to identify the entry and aid with wayfinding, the latter for both the Recreation Center and public spaces, in general.

During the meeting, the team requested five departures. The departures related to rooftop features placed closer to the rooftop edge, a reduction of large vehicle spaces, an increased lot line setback, a longer unmodulated facade close to the street line and an increased podium height for the west building. The Board indicated potential support for all five departures as requested. 

During the meeting, the Board also requested the team produce complete renderings of the pedestrian experience as it relates to the “Slow Cut” approach, as well as sun studies of the public access easement area. They also requested complete architectural and material details, particularly with the cladding and glazing systems proposed for the project.

At the conclusion of the meeting, the Board voted the project return for a second recommendation meeting, giving the team another opportunity to refine the project in response to the guidance given.