In Everett, Washington, stands the world’s largest building, a massive factory that boasts a size of over 472 million cubic feet and houses the renowned Boeing facility. Since its establishment in 1967, the plant has manufactured over 5,000 wide-bodied aircraft, surpassing its closest competitor, the Tesla Gigafactory, by 33%.
Covering an impressive 98 acres of land, the Boeing factory dwarfs the original Disneyland resort in Anaheim, California, which occupies approximately 85 acres. The idea for this colossal facility was conceived by Boeing’s President and Chairman, William M. Allen, who recognized the need for a new type of manufacturing space to construct the groundbreaking 747 aircraft.
The construction of this behemoth factory was completed in just over 12 months, costing more than $1 billion, which exceeded Boeing’s total value at the time. The sheer magnitude of the project required moving 4 million cubic yards of earth, necessitating the creation of a specialized railway line for the excavation process.
The facility’s scale is so immense that it could comfortably accommodate Disneyland within its walls. Initially generating its own microclimate, with clouds forming beneath its 90-foot-high roof due to moisture build-up, the factory now relies on modern air conditioning to regulate its environment.
Boasting two significant expansions in 1978 and 1992 to accommodate the production of the Boeing 767 and 777, respectively, the factory has recently added additional structures to support the manufacturing of the new 777X. The site, which currently hosts around 36,000 employees on a daily basis, operates across three shifts, offering various amenities and services beyond aircraft production.
The factory’s popularity extends to its guided tours, which attracted 239,579 visitors in 2024 alone. The tours provide insight into the intricate workings of the production floor while allowing employees to navigate the vast facility through a network of underground tunnels and provided bicycles.
With multiple vans and extensive overhead crane systems in place, the facility moves aircraft along the production line at a steady pace. The final stage of aircraft production involves meticulous painting processes, with a 747 requiring approximately 454 liters of paint and a 787 needing around 370 liters. Boeing anticipates delivering the first 777X to airlines by 2027, with a total of 619 orders placed for both passenger and cargo variants as of November 2025.
