Updated Thursday, November 29, 2012 at 11:46 PM
Seattle planners have approved Amazon.com’s proposed three-block high-rise office campus in the Denny Triangle.
The key approval from the Department of Planning and Development came in a 50-page decision published Thursday and is expected to clear the way for Amazon to close on purchase of the blocks from Clise Properties by Dec. 31.
Amazon and its consultants already have begun seeking demolition and excavation permits for construction on the first block, which could start next year.
The three blocks are bounded roughly by Sixth Avenue, Westlake Avenue and Blanchard Street.
Amazon wants to build a 37- or 38-story tower and a smaller building on each of the three blocks, for a total of 3.3 million square feet of office space. Amazon’s architects have said the complex could take six years or more to complete.
The massive office project — downtown Seattle’s largest ever — also would have 53,000 square feet of shops and restaurants as well as underground parking for 3,300 cars. Open space spread over the three blocks would total more than an acre and be accessible to the public.
Amazon signed a contract in late January to buy the three blocks from longtime owner Clise. The fast-growing online retailer also has options or first-offer rights on the equivalent of three more Clise blocks to the northwest.
The city planning department imposed a number of conditions on Amazon, including further refinements to the design of buildings on the last block scheduled for development.
Members of the city’s Downtown Design Review Board expressed concerns about that block before they approved the three-block project in September.
Amazon also will pay the operating cost for an additional car for the city’s South Lake Union streetcar for 10 years, providing more frequent service. There’s a streetcar stop on the proposed campus, and Amazon will be a major employer at both ends of the line.
The company is expected to close on purchase of its leased, 1.8 million-square-foot South Lake Union headquarters complex by the end of the year as well. Amazon is paying Vulcan Real Estate $1.16 billion for the 11 buildings.
The company also leases or has committed to lease more than 1 million square feet elsewhere in the Denny Triangle and South Lake Union.
Eric Pryne: email@example.com or 206-464-2231