One of the largest manufacturing complexes in the world is about to expand.

Boeing proposes to begin demolition of some office buildings on its Everett site next month to make way for a new, 1.3 million-square-foot composite-wing facility for its 777X airplane.

In that facility, the Everett plant will for the first time fabricate large carbon-fiber airplane structures, the technology of the future for jet airliners.

Plans submitted to the city of Everett also reveal that Boeing intends to add to the giant manufacturing site another, previously undisclosed assembly building, where mechanics will complete assembly of the 777X.

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That 350,000-square-foot airplane assembly building will be located just east of the current assembly building.

Composite-wing facility

The land-use application submitted to the city at the end of March shows the wing facility will be to the rear of the current large assembly building and the same height as that building, 115 feet.

About 1,000 people will work there initially. At peak, it could employ up to 3,000, Boeing’s submission projects.

During construction over the next couple of years, “up to 2,000 construction workers on a 24/7 schedule” will work on the wing building.

They will haul in 700,000 cubic yards of fill to level the site.

The facility they’ll build is where Boeing will fabricate the 777X’s giant wings, which are each 114 feet long and made from carbon-fiber-reinforced plastic.

The fabrication technology involves robotic machines in a dust-free facility applying layers of epoxy-resin-infused carbon fiber to a mold. The resultant structure is then baked to hardness in a high-pressure oven called an autoclave.

Boeing’s plan calls for “three large autoclaves, a clean room and an overhead crane system.”

Demolition of three existing office buildings on the Everett site is projected to begin May 1, with construction of the new facility to start in November. Boeing’s timeline shows autoclaves installed in mid-2015 and the building complete by mid-2016.

Production of the 777X is set to begin in 2017, with first delivery targeted for 2020.

Parking crunch

The wing facility will include 120,000 square feet of infrastructure and office space. Nevertheless, as the existing offices in that location are demolished, some 2,500 to 3,000 Boeing workers will be displaced to other office space “outside the southwest Everett subarea.”

Real-estate-industry sources say Boeing is considering leasing between 150,000 and 250,000 square feet in the Interstate 90 corridor and as much as 300,000 square feet in Bothell. The Everett site will also lose about 1,700 employee parking stalls, swallowed up by the new building.

The Boeing application notes that some of the parking lost will be mitigated by the office workers who move out. In addition, it is negotiating to lease 1,000 parking spaces near its site and will arrange shuttle buses from parking areas in the south end of Paine Field.

Allan Giffen, director of the city of Everett Planning Department, said his office will likely have the land-use application processed within a couple of weeks.

Dominic Gates: (206) 464-2963 or

Seattle Times commercial real-estate reporter Sanjay Bhatt contributed to this story.