A colossal factory covering over 472 million cubic feet holds the title as the world’s largest structure and boasts a unique microclimate. The expansive Boeing facility in Everett, Washington, surpasses the Tesla Gigafactory by 33% and has manufactured over 5,000 wide-bodied aircraft since its inception in 1967.
Encompassing 98 acres of land, the impressive site is larger than the original Disneyland resort in Anaheim, California. The establishment came to fruition when Boeing’s then-President and Chairman, William M. Allen, acknowledged the necessity for a new type of manufacturing space to construct the groundbreaking 747 aircraft, which was significantly larger than any existing passenger plane at the time.
After exploring various potential locations, the company chose a decommissioned military airfield just 22 miles from its main offices. The construction process, completed in slightly over 12 months at a cost exceeding $1 billion, involved moving an immense 4 million cubic yards of earth, requiring a specially built railway line to transport the excavated material.
The resultant factory, larger than Disneyland, developed its microclimate, with clouds forming under its 90-foot-high roof due to moisture accumulation initially. However, modern air conditioning systems have eliminated this phenomenon. Bonnie Hilory, executive director of the Future of Flight Foundation, described the factory as Boeing’s “best product,” emphasizing its immense scale, massive manufacturing capabilities, and housing of giant aircraft.
The factory, which has expanded twice to accommodate production of Boeing 767 and 777 aircraft, now includes additional buildings for robotic assembly and wing manufacturing for the 777X model. Approximately 36,000 employees work in shifts at the site, with various supporting facilities such as fire services, childcare, and medical centers.
Visitors can take guided tours of the factory, with over 239,000 visitors paying for the experience in 2024. The facility features underground tunnels for employee movement, over a thousand bicycles for navigation, and numerous vans for transport. The site’s production floor includes button-operated doors and overhead cranes to aid in the aircraft assembly process.
The painting stage of manufacturing can take up to a week, with a 747 requiring around 454 liters of paint and a 787 needing approximately 370 liters. Boeing aims to deliver the first 777X to airlines by 2027, with a total of 619 orders received as of November 2025 for both passenger and cargo versions of the aircraft.