tentatively plans to start building the first phase of its three-block office complex in Seattle's Denny Triangle next year, and could break ground on the second and third phases at two-year intervals.

Share story tentatively plans to start building the first phase of its three-block office complex in Seattle’s Denny Triangle next year and could break ground on the second and third phases at two-year intervals, according to a document filed recently with city planners.

The timetable — more specific than anything Amazon has previously disclosed — is included in a preliminary study of the mammoth project’s environmental impacts. It was prepared by Amazon consultants under the direction of the city’s Department of Planning and Development.

The document estimates that, when all three blocks are developed, 12,000 people will work there.

The study also reveals the Amazon project has a name: Rufus 2.0. Amazon representatives did not return a call late Friday seeking an explanation.

But the company has named a building in its new South Lake Union headquarters complex Rufus. And the online retailer’s website contains a tribute to “Our Friend Rufus” — a dog, apparently a Corgi, who was “a fixture at, dating back to the early days in the company’s history.”

Rufus, who accompanied his owner to work every day, died in 2009. The tribute credits him with “starting up the dog-friendly culture at Employees who bring their four-legged friends to work today have Rufus to thank.”

The new complex would include 3.3 million square feet of office space, mostly in three 38-story towers, plus 66,000 square feet of shop and restaurant space, 3,300 underground-parking stalls, and about 1.7 acres of public open space, including plazas and pocket parks.

The environmental study says the block bounded by Sixth and Seventh avenues and Virginia and Lenora streets would be developed first, followed by the block just north of that, between Lenora and Blanchard streets.

The block between Lenora, Blanchard, Seventh Avenue and Eighth Avenue would be developed last.

Amazon has a tentative deal to buy all three blocks — now mostly parking lots — from Clise Properties, their longtime owner.

The environmental study also estimates about 25 percent of the trips to and from Rufus 2.0 during morning and evening peak hours would be by car, with transit, bicycling and walking accounting for the rest.

Even so, the project still would make traffic congestion worse, the study adds, especially at the closest intersections.

But that could be mitigated by adding a left-turn lane at Seventh and Blanchard and changing signal timing, it says.

Traffic farther away also would be affected, the study says. In 2020, it calculates, Rufus 2.0 would increase delays 53 seconds during the peak afternoon commute hour at Yale Avenue and Howell Street, a major approach to southbound Interstate 5.

The environmental study also say Amazon’s towers would not disrupt any city-protected views from public viewpoints.

The city’s advisory Downtown Design Review Board, which has held two meetings to consider the project’s design, has tentatively scheduled a third July 10.

Eric Pryne: 206-464-2231 or