Amazon.com poised to take another Seattle high-rise

West 8th

Seattle’s burgeoning South Lake Union neighborhood might just not be big enough for Amazon.com, at least for now. The online retailer, which moved its headquarters to the redeveloped quadrant of Seattle earlier this year, is expanding beyond its 11-building campus.

A real estate source says that Amazon has secured 300,000 square feet of new office space at the West 8th building, located at 8th and Westlake avenues. The two-year-old, 28-story high-rise — on the streetcar line that connects downtown Seattle to South Lake Union — also houses the Casey Family Programs and Salesforce.com.

At 300,000 square feet, the space has enough room to house up to 1,200 workers. We previously reported on Amazon’s interest in West 8th in July, following news that the company had secured 416,000 square feet at the nearby 1918 Eighth Avenue building.

Clay Nielsen, a broker at Washington Partners who works with Amazon.com, declined to comment on the West 8th property or the company’s other expansion plans in the city. Representatives at Amazon and Pacific Real Estate Properties — which handles leasing for the building — did not respond to requests for comment.

In addition to West 8th, real estate sources say that Amazon is eyeing the former Onvia headquarters at 1260 Mercer Street, described on the property owner’s Web site as being located “mere blocks from Amazon.com’s new world headquarters in Seattle’s South Lake Union neighborhood.”

Brokers who have looked at placing tenants at West 8th in recent weeks have been told that space is no longer available because of a commitment from a large online retailer.

Meanwhile, The Seattle Times reports that real estate developers are kicking off a new round of construction in the South Lake Union neighborhood. One of those developers, Touchstone, which is proposing two 12-story office towers on the Troy Laundry block, also owns West 8th. Representatives for Touchstone could not be immediately reached.

There’s no indication that Amazon is looking at the new properties in South Lake Union, but real estate sources say that the online retailer is on the prowl for more space to keep up with its growth spurt. Amazon has been on a roll lately with the launch of its Kindle Fire, and a stock price that has soared 21 percent this year.

During the first three months of the year, the company added 4,200 employees.

Vulcan, the investment arm of billionaire Paul Allen, the largest landowner in South Lake Union, still owns about 25 acres that could be developed into office, biotech, residential or real estate space. In total, Vulcan spokesman David Postman said that they have capacity for about five million square feet of development on the various sites in the neighborhood.

“The timing of the development will depend on market demand, of course,” said Postman, who referred questions about Amazon’s future growth in the neighborhood to the online retailer.