Home AEC 10-Story Office and Research Building Proposed by Alexandria Real Estate in Seattle’s...

10-Story Office and Research Building Proposed by Alexandria Real Estate in Seattle’s South Lake Union Neighborhood Moves to Recommendation Phase

Alexandria Real Estate, South Lake Union, ZGF Architects, Site Workshop, Seattle, University of Washington Medicine, Facebook
Rendering Courtesy of ZGF Architects

By Bekka Wiedenmeyer

Seattle’s South Lake Union neighborhood is home to a variety of building types which front the marine bay ecosystem of Lake Union. In the past, maritime purposes typified the area, but in the last 10 years it has been redeveloped with office, commercial, residential and mixed-use buildings either under review or recently constructed, intermixed with a more pedestrian orientation. In July, ZGF Architects, the lead architecture firm, and Site Workshop, the project’s landscape architect, proposed a revised project for a 10-story high-rise structure with a penthouse level to accommodate office and research laboratory uses during a second early design guidance meeting to the West Design Review Board, based on the suggestions made in the first EDG meeting in April 2019. In response, the Board recommended the project move forward to the recommendation stage. 

The site, which is owned by Alexandria Real Estate and located at 701 Dexter Avenue N., is currently occupied by a six-story reinforced concrete structure and on-grade parking built in the 1980s. The building and parking are scheduled to be demolished to make way for the new high-rise structure. Surrounding the site are three streets, each with their own characteristics and architecture. To the south, Dexter Avenue N. has larger scale buildings used primarily for office and research purposes, including Facebook Dexter and UW Medicine at South Lake Union. This avenue represents an important north-south pedestrian, biking and vehicle corridor in South Lake Union. To the west, Aurora Avenue N. also has larger scale buildings, but is predominantly designated as a non-porous “freeway,” a barrier to the neighborhood with limited pedestrian activity. To the east, Roy Street establishes a vital pedestrian and bike connection to Lake Union Park and will serve as a visual gateway for the site from the south, east and north.

According to project documents, the 180,950 square foot high-rise building will include 10 tower floors for office or research laboratory use, sustainable with minimum LEED Gold certification, with a penthouse and rooftop amenities. The project also proposes 230 stalls of below-grade parking. Other amenities include ground level entries along Dexter Avenue and Roy Street which will provide access to a building lobby, retail space and office elevator lobbies. The southeast corner of the site will be designed as a network of bike lanes, featuring mezzanine bicycle storage and locker/shower rooms in the center of the lobby, to celebrate the spirit of innovation embraced by the South Lake Union neighborhood. Goals of the project, as outlined in the documents, are redevelopment with a focus on the health and well-being of building occupants, and pedestrian activation at street level as the site represents a gateway with the facade at Dexter and Roy.

ZGF Architects in its revised proposal describes the building as having two discrete components: a bigger, “quieter” massing option to ground the structure to the site at the west, with a modulated east mass with smaller projecting volumes to engage Dexter and Roy. More modulation and intermediate scaling will be implemented at Dexter and Roy to aid the vision of the site as a gateway, with modulation and setback at Aurora for cohesive massing, as the documents state. The modulated north facade is proposed to have setbacks, with the material changing from opaque to glazed surfaces. To blend with the natural, maritime character of many of the neighborhood’s buildings, the project also aims to use steel and wood detailing to complement the glazing surfaces.

In the first EDG meeting, the Board did not particularly support any of the massing options, noting both merits and concerns of each. While the Board did not specifically support any option moving forward to the second EDG meeting, they did like the massing option with split components, but asked the team to clarify the design to address concerns regarding the overall height, bulk and scale of the project as it relates to the site’s transitional nature along Dexter, the modulation approach along Roy and the potential pinched condition along Aurora as the site sloped up. 

The revised project addressed these concerns, with the clarification of the two distinct components of the structure in accordance with conceptual references along Aurora, Dexter and the overall South Lake Union neighborhood, according to the documents. The height, bulk and scale were reduced, with the height of the NE stair and elevator massing remaining at or below the adjacent heights of roof elements at nearby Dexter Yard. The team also introduced a full height setback at the NW corner at Aurora to give more room to future residences at 701 Valley. The team also proposed a wrapping offset at the Aurora-Roy corner to represent an appropriately scaled visual marker and more cohesive building massing, according to the documents. 

The Board appreciated these efforts made by the team in the second EDG meeting to address the concerns raised in the first meeting. Moving forward, they suggested also refining the mass, scale, configuration, dimension and proportion of the projecting elements, as the report states. They also recommended wrapping the box language around the northeast corner to address the height, bulk, scale and potential blank wall condition of the stair tower.

At the conclusion of the second EDG meeting, the Board recommended the project move forward to the recommendation phase, putting Alexandria, ZGF Architects and Site Workshop one step closer to creating a project that focuses on the health and lifestyle of building occupants while acting as a visual gateway for the South Lake Union neighborhood.