A massive factory spanning over 472 million cubic feet has earned the distinction of being the largest building globally, with enough space to house Disneyland comfortably. Located in Everett, Washington, the Boeing facility outstrips its nearest competitor, the Tesla Gigafactory, by 33%. Since its establishment in 1967, the facility has produced more than 5,000 wide-bodied aircraft.
Covering an expanse of 98 acres, the site is larger than the original Disneyland resort in Anaheim, California, which occupies approximately 85 acres. The idea for the plant emerged when Boeing’s then-President and Chairman, William M. Allen, recognized the necessity for a new type of manufacturing space to create the revolutionary 747 aircraft, which was significantly larger than any existing passenger planes at the time.
After evaluating various locations for the facility, including one in California, Boeing chose a disused military airfield just 22 miles from its Seattle headquarters. Construction of the facility, completed in just over 12 months, cost over $1 billion, exceeding Boeing’s total worth at the time. The factory’s vast size required the movement of 4 million cubic yards of earth, necessitating a custom-built railway line for transporting the excavated material.
The factory’s immense scale is highlighted by its ability to accommodate Disneyland within its confines and create a unique microclimate. Although clouds used to form under its 90ft-high roof due to moisture accumulation, modern air conditioning systems have eliminated this phenomenon. The executive director of the Future of Flight Foundation, Bonnie Hilory, lauded the factory as Boeing’s “best product,” emphasizing its sheer size and manufacturing capabilities.
Since its initial construction, the factory has undergone two significant expansions to support the production of Boeing 767 and 777 aircraft. In 2024, approximately 36,000 workers across three shifts operate at the facility, with some engaged in auxiliary services like firefighting, banking, and childcare. Guided tours of the factory have gained popularity, with over 230,000 visitors paying for the experience annually.
The extensive underground passages spanning over two miles allow Boeing staff to move between different areas without disrupting aircraft manufacturing. A fleet of overhead cranes, covering 31 miles of rails, assists in maneuvering the aircraft along the assembly line. The meticulous painting process for each aircraft can take up to a week, with a 747 requiring around 454 liters of paint and a 787 needing approximately 370 liters.
Boeing plans to deliver its first 777X aircraft to customers by 2027, with a total of 619 orders for passenger and freighter versions as of November 2025.