The world's largest 3D-printed construction project is currently underway in Qatar. The effort involves printing a pair of schools, each of which smashes current records for a 3D-printed building.
The 3D Printed Schools Project is headed by UCC Holding, in partnership with Qatar's Public Works Authority. The former commissioned leading 3D-printed construction firm COBOD to produce two customized BODXL printers, each measuring 50 m (164 ft) in length, having a width of 30 m (98 ft), and standing 15 m (49 ft) tall. There are actually 14 schools being built in all, two of which are being constructed using the 3D printers.
As with other 3D-printed buildings we've seen, the two schools will be formed by the printers extruding a cement-like mixture out of a robotically controlled nozzle in layers, following a blueprint and building up the structure. Once this process is complete, human builders will then move in to add a roof, doors, windows and everything else required to turn a structural shell into a school.
"The project involves the construction of 14 public schools, including two built using 3D printing technology, each with a built-up area of 20,000 square meters [215,000 sq ft] — totaling 40,000 square meters [430,500 sq ft]," says UCC Holding. "This is 40 times larger than the largest 3D-printed building constructed anywhere in the world to date. The two schools are designed as two-story buildings on plots measuring 100 by 100 meters [328 by 328 ft] each, making this project an unprecedented model for future-ready educational infrastructure in Qatar and across the region."

Due to the decentralized nature of 3D-printed construction, it's extremely difficult to verify the claim of the schools being 40 times larger than any other 3D-printed project, but these things are definitely huge and are indeed the largest we've seen to date.
Unfortunately, a press representative told us that no renders are available of the school designs yet, though we know that they are inspired by the natural desert formations of Qatar and upon completion will feature curved, flowing walls resembling dunes.
Construction of the whole 14-school project is due to be completed by the end of 2025, and more details are expected in the coming months.
Sources: COBOD, UCC Holding