A Japanese rail station's printed shell goes up overnight, between the last train and the first

ARIDA, Japan, March 26, 2025 — Serendix says it put up the printed shell of a new station building at Hatsushima on JR West's Kisei Line overnight, starting after the last train left at 11:57 p.m. and finishing by 5 a.m. Here's what happened, what it cost, and what went wrong.

Cost and outcome (as of Apr. 21, 2025)

Outcome: Station shell assembled overnight on March 25–26, 2025, per Serendix; fit-out and ticket gates to follow, with service planned around July 2025. (Serendix release on PR Times, Apr. 21, 2025)
Cost: Not published. Serendix says it and JR West will study the savings in build time and construction and maintenance costs. (Serendix release on PR Times, Apr. 21, 2025)
Comparison: Serendix says a reinforced-concrete station body normally takes one to two months to put up. (Serendix release on PR Times, Apr. 21, 2025)

Why a station had to go up at night

The current Hatsushima station is a wooden building completed in 1948, according to Serendix. It's now unstaffed, and aging had made upkeep costly. Work on buildings next to the track generally has to happen at night, when no trains run, so a reinforced-concrete station body usually takes one to two months to put up. Serendix says the goal here was to finish the structure, foundations included, in the roughly six hours between the last train and the first. Foundation work normally takes two weeks to a month including curing time, the company says. (Serendix release on PR Times, Apr. 21, 2025)

Serendix says that when the six-hour target was first set, everyone involved in development said it was "impossible." The company points to its earlier record of finishing a printed house in under 24 hours. (Serendix release on PR Times, Apr. 21, 2025)

How the parts were made

The station's parts were made at a partner factory, Tateo Densetsu, in Minamata, Kumamoto Prefecture. A construction 3D printer extruded a special mortar from a nozzle on a robot arm. Rebar and concrete were then placed inside the printed parts to bind them and add strength. Making the four parts took seven days, and they were trucked to the site. (Serendix release on PR Times, Apr. 21, 2025)

The design is credited to architect Hiroshi Ota of Nuub and to JR West's Osaka architects office. (Serendix release on PR Times, Apr. 21, 2025)

The overnight build

After the last train left at 11:57 p.m. on March 25, JR West blocked trains from entering the track and work began. Four trucks took turns pulling into the station forecourt, and a crane lifted each part off its truck and set it directly in place. Assembly took about two hours, Serendix says, but about 45 minutes of that was swapping trucks, so net work time was about an hour and 15 minutes. After removing transport fittings and fixing the parts, crews finished at 5 a.m. on March 26. (Serendix release on PR Times, Apr. 21, 2025)

In the following days JR West ran technical checks, and Serendix made the minor repairs it was asked to make. JR West is handling the exterior, interior and wiring for ticket gates, with service planned around July 2025. (Serendix release on PR Times, Apr. 21, 2025)

About the builder

Serendix says its first model, the serendix10, was completed in 23 hours of work in March 2022. It formed a capital and business alliance with the JR West group in May 2024, and in September 2024 it built its first serendix50 two-person home, a recovery-housing model, in Suzu, Ishikawa. (Serendix release on PR Times, Apr. 21, 2025)

What went wrong

Repairs after the build. JR West's technical review found issues that needed minor repairs, which Serendix says it carried out. (Serendix release on PR Times, Apr. 21, 2025)
Foundations unclear. The release says all planned work was done between the last and first trains, but it doesn't say how the foundations were handled within that window. (Serendix release on PR Times, Apr. 21, 2025)
No numbers on cost. Serendix gives no construction or maintenance cost for the station, against the wooden one or a conventional rebuild.
What we don't know yet: whether the station opened to passengers in July 2025, and what it cost.

Our follow-up question for JR West

Did Hatsushima open to passengers as planned, and what did the printed station cost against a conventional rebuild?

Sources

Serendix Inc., “世界初の3Dプリンター駅舎、JR初島駅の建設を完了” (in Japanese), PR Times, Apr. 21, 2025. prtimes.jp

Disclosure: [not in copy] Editor placeholder