The building that had to be built first
Built in 1967 for the 747, Everett covers 98.3 acres and encloses 472 million cubic feet — the largest building in the world by volume.
When Boeing agreed to build the 747, it had nowhere to build it. Every building the company owned was too small, and the aircraft was already sold — Pan Am had ordered 25 in April 1966.
So the factory came first, sort of. Boeing cleared forest at Paine Field, Everett, and put up the assembly plant and the aeroplane more or less simultaneously, starting production before the building was finished.
The numbers
| Volume | 472,370,319 cu ft (13,376,038 m³) |
| Floor area | 98.3 acres (398,000 m²) |
| Built | 1967 |
| Hangar doors | Six, each 82 ft tall and 300–350 ft wide |
| Tunnels beneath the floor | 2.33 miles (3.75 km) |
| Workforce (2022) | around 30,000 across three shifts |
It is the largest building in the world by volume — a measure that matters more than floor area here, because what the 747 needed was height and clear span, not just acreage. The overhead cranes have to lift a complete 747 wing, and the doors have to let a finished aircraft out.
The 2.33 miles of tunnels underneath carry people and services, so the floor above stays clear for aeroplanes.
Why this was a serious risk
Boeing was committing, at once, to:
- an aircraft roughly twice the size of anything then flying;
- a factory that did not exist, on a site that was forest;
- a schedule of about four years; and
- an engine — the JT9D — that was itself a first of its kind.
The engineering team under Joe Sutter got from launch to first flight in roughly 28 months. They became known inside the company as “the Incredibles”, and the name has stuck for sixty years.
The aircraft first flew from Paine Field on 9 February 1969.
What it built afterwards
The 747 line ran at Everett for 54 years. The last one rolled out in December 2022 and was delivered to Atlas Air on 31 January 2023 — number 1,574.
The building did not go quiet. Everett has also assembled the 767, the 777 and 777X, and the 787 before that line moved to South Carolina in 2021. In 2026 it took on 737 MAX assembly as well.
So the building put up for one aeroplane has now outlived it, and is busier than ever.
Related
Frequently asked questions
- What is the largest building in the world?
- By volume, the Boeing Everett Factory in Washington State. It encloses 472,370,319 cubic feet (13,376,038 m³) and covers 98.3 acres (398,000 m²). It was built in 1967 because Boeing had nowhere large enough to assemble the 747.
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