Boeing's factory in Everett, Washington, is the world's largest building by volume, spanning over 472 million cubic feet and covering 98 acres. The facility is so vast that Disneyland, which occupies roughly 85 acres, could fit comfortably inside. It surpasses the Tesla Gigafactory by 33% in size and has produced more than 5,000 wide-bodied aircraft since opening in 1967.
The plant was built to manufacture the Boeing 747, a 'jumbo jet' two-and-a-half times larger than existing passenger planes. Construction took just over 12 months and cost over $1 billion (£740 million), exceeding Boeing's entire value at the time. The project required moving 4 million cubic yards of earth, with a purpose-built railway line to transport excavated material.
During its early days, the factory generated its own microclimate: clouds formed beneath its 90ft-high roof due to moisture accumulation. Modern air conditioning has since eliminated this phenomenon. The facility has expanded twice—in 1978 for the Boeing 767 and in 1992 for the Boeing 777—and now includes structures for robotic assembly and composite wing production for the 777X.
As of 2024, around 36,000 workers operate across three shifts at the site. The factory complex includes its own fire brigade, banking facilities, childcare centres, medical surgery, and water treatment works. An underground tunnel network stretching over two miles allows staff to move between sections without disrupting production, with more than a thousand bicycles available for travel.
The factory offers tours, which attracted 239,579 visitors in the past year, each paying $20 (£15). Bonnie Hilory, executive director of the Future of Flight Foundation, described the facility as Boeing's 'best product,' emphasising its scale. Visitors David and Georgiana King from Sussex took the tour twice, noting changes in technology since their first visit a decade ago.
