SEATTLE-Vulcan Real Estate has completed the 545,000-square-foot fourth phase of the 1.7-million-square-foot Amazon.com headquarters in the South Lake Union district, a phase that includes 25,000 square feet of street-level retail space in addition to the new class A office space. A total of 10 buildings in the first four phases are now finished, and the final office building is set to open in 2013. The entire headquarters consists of nine new buildings and two historic renovations.

Ada M. Healey, vice president of real estate at Vulcan Inc., said in an announcement that the new headquarters is designed to provide "a sustainable and collaborative work environment for Amazon.com employees." She cited a public-private partnership with the City of Seattle and South Lake Union community that enabled the development to proceed.

Located on the block bordered by Harrison Street, Thomas Street, Terry Avenue N. and Boren Avenue, phase four of Amazon.com’s headquarters includes two new office buildings and one historic building. The project team for the fourth phase includes Callison as the architect and GLY as the contractor.

The fourth phase features the tallest structures in Amazon.com’s headquarters with two 12-story, 160-feet high buildings. As part of the Seattle City Council’s approval for increased building heights on the last two phases, Vulcan is paying $6.4 million to the city for affordable housing and day care needs. Of that amount, $5.7 million is dedicated to affordable housing, a portion of which will be used by Plymouth Housing Group and Capitol Hill Housing to preserve and upgrade two low-income housing projects as well as to construct a new low income housing project in South Lake Union.

The phase four site also incorporates the historic Terry Avenue Building, a two-story brick structure dating to 1915 and designated a historic landmark in 2008. The renovated building anchors the through-block connection that negotiates the site’s 25-foot grade change, connecting to a scenic outdoor courtyard and landscaped plazas. Featuring retail uses on both floors with outdoor seating, the building will be home to three new Tom Douglas restaurants opening in April: an Italian pasta restaurant (Cuoco), a sports bar/tavern (Brave Horse Tavern) and a Tibetan dumpling restaurant (Ting MoMo).

The phase four buildings are expected to earn LEED Gold certification; phases two and three of the headquarters have already achieved LEED Gold. The Terry Avenue Building also features Seattle’s first green roof on a historic landmark building. South Lake Union is also expected to become a certified green neighborhood as part of the U.S. Green Building Council’s LEED for Neighborhood Development national certification program.

The entire Amazon.com headquarters includes 11 buildings totaling nearly 1.7 million square feet of office and 100,000 square feet of street-level retail space. In addition, Amazon.com occupies about 180,000 square feet of office space at Vulcan’s 2201 Westlake building, bringing the company’s total footprint in South Lake Union to 1.9 million square feet. All of the buildings are located on the Seattle Streetcar line which connects riders to the bus tunnel and light rail.