Structure Type: built works - dwellings - houses - apartment houses

Designers: Bosa Development Corporation (firm); Hart Crowser (firm); Natale Bosa (developer)

Dates: constructed 2014-2016

41 stories, total floor area: 960,000 sq. ft.

5th Avenue
Downtown, Seattle, WA

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Overview

Insignia Towers was an early project serving the expanding number of high-tech workers drawn to jobs at Amazon.com and other high-tech employers in Seattle after the Recession of 2008. Between July 2012 and July 2013, construction inventory of condominiums escalated by 350 per cent. Anyone living in the city at this time, well remembers the 50+ cranes lining the skyline by the mid-2010s. Insignia would remain one of the tallest and most apparent apartment towers in the northern end of the Downtown Seattle area. Sales at Insignia proved very brisk, selling out soon after completion of the North Tower in late 2016, prompting Bosa Development to look for other building opportunities in the Puget Sound region.

Building History

Embassy Development Company of Vancouver, BC, backed this high-rise project beginning in 2007, but the economic collapse of 2008 put a halt to the company's plans. By 2012, interest in the project had revived, as Seattle's Amazon office building spree had become a stable feature of the local economy. Condominiums and rental apartment projects sprouted up everywhere in Downtown Seattle and South Lake Union to provide housing for hordes of incoming Amazon and other high-tech employees. Bosa Development of Vancouver, BC, took over the project and planned two 40-story towers for the site at 2301 6th Avenue. Construction began with diggning and shoring up foundations in 2012, with the first (south) tower built between 2013 and 2015 and the second (north) begun in 2014 and finished in 2016. When completed, Bosa emphasized that Insignia would be the largest condo project in the Pacific Northwest.

The industry web site Construction Today.com described the towers' capacities: "Among the development’s residences will be 101 one-bedroom units, 106 one-bedroom-plus-den units, 299 two-bedroom units and 109 two bedroom-plus-den units. Two units will have three bedrooms plus a den. Unit sizes will range from approximately 737 square feet to 2,311 square feet, and the bedrooms are larger than most condominiums in the area. Prices will range from the high $400,000s to approximately $2 million for penthouse units. Four penthouse units will be located on the 40th floor of the first tower, and additional penthouse units will be on floors 37 to 40 of the second tower. The Insignia will include approximately 1,050 parking stalls including three levels of below-grade and six levels of above-grade parking." (See Construction Today.com, "Bosa Development – Insignia in Seattle," published 02/05/2015, accessed 09/05/2018.)

Bridget Miller served as Bosa Development's Project Executive on the Insignia Towers. Bosa served as its own general contractor on the Insignia Towers. "Because the Insignia is Bosa Development’s first project in Seattle, the company – which acts as its own general contractor – has been establishing relationships with the construction community in the city. Miller estimates up to 50 subcontracting companies will work on the project. Although rain is always expected in Seattle, the city reportedly experienced an unusual amount during excavation of the project." (See Construction Today.com, "Bosa Development – Insignia in Seattle," published 02/05/2015, accessed 09/05/2018.) This unexpectedly heavy rain slowed efforts at laying the foundation on the entire block site. One side of the site backed up against the Seattle Center Monorail on 5th Avenue.

Building Notes

This twin-tower apartment project was, like another contemporary twin building, the Heron-Pagoda Towers, was sited on 5th Avenue in Downtown, Seattle, WA.

According to the web site of Hart Crowser, the Insignia Towers' geotechnical engineers: the firm performed the following services: "The project required mass excavation for 3 to 4 levels of underground parking over an entire city block bordered by Fifth Avenue, Sixth Avenue, Bell Street, and Battery Street. The solder pile and tieback shoring system was designed and installed to minimize the impact to the adjacent Battery Street Tunnel and Monorail guideway foundations. Hart Crowser provided site-specific seismic design criteria in support of the City of Seattle-mandated seismic design peer review process." (See Hart Crowser.com, "Insignia Towers," accessed 09/05/2018.)

PCAD id: 11267