A colossal factory, spanning over 472 million cubic feet, holds the title as the largest building globally, boasting its own microclimate. Situated in Everett, Washington, the expansive Boeing facility surpasses the Tesla Gigafactory by 33% and has manufactured over 5,000 wide-bodied aircraft since its establishment in 1967.
Covering 98 acres, the site is larger than the original Disneyland resort in Anaheim, California, showcasing the visionary thinking of Boeing’s then-President and Chairman, William M. Allen, who foresaw the need for a groundbreaking manufacturing space to construct the revolutionary 747 aircraft, which was significantly larger than any existing passenger planes at the time.
After exploring various locations, Boeing selected a disused military airfield just 22 miles from its Seattle headquarters to build the immense facility. Constructed in just over a year at a cost exceeding $1 billion, the factory required moving 4 million cubic yards of earth, necessitating a custom-built railway line for excavation removal.
The factory’s sheer scale is evident as it could comfortably house Disneyland within its walls and even developed its microclimate initially, with clouds forming beneath its 90-foot-high roof due to moisture buildup. Over time, modern air conditioning systems have replaced this phenomenon.
With two major expansions in 1978 and 1992 to accommodate the production of Boeing 767 and 777 aircraft, respectively, the facility now includes additional buildings for the robotic assembly of the 777’s fuselage and manufacturing of composite wings for the latest 777X model.
Currently, around 36,000 employees work in shifts at the vast site, with various support services available alongside aircraft production. The factory offers guided tours, attracting over 200,000 visitors annually, showcasing the technological advancements and scale of Boeing’s operations.
Utilizing an intricate network of underground tunnels and bicycles for employee transport within the facility, Boeing ensures seamless aircraft assembly. The production line, equipped with overhead cranes, moves aircraft at a steady pace towards completion, with the painting process alone taking up to a week.
Boeing projects the first 777X delivery to airlines by 2027, with 619 orders already received for passenger and cargo variants as of November 2025. The factory’s continued growth and innovation highlight its significance as a leading hub for aircraft manufacturing and technology.
