Japan has completed its first government-approved two-storey house built with 3D printed reinforced concrete. The project shows that robotic construction can meet the country’s strict seismic regulations. Construction technology company Kizuki developed the house together with ONOCOM, using a large-scale COBOD construction printer. The project marks an important step for 3D construction printing (3DCP) in earthquake-prone regions.

The experimental house stands in Kurihara City, Miyagi Prefecture. It has a total floor area of about 50 m², with 31 m² on the ground floor and 19 m² on the upper floor.

The printer created the reinforced concrete walls layer by layer directly on site. The result proves that automated construction can deliver structurally reliable buildings while meeting demanding building regulations.

Integrating Structure, Design And Building Services

Traditional reinforced concrete construction requires many steps. Builders first create formwork, then add reinforcement, pour concrete, and remove the moulds afterwards. The 3D printing process simplifies this workflow. A single construction printer produces the walls while integrating structural and functional layers at the same time.

The project uses a three-layer wall system that combines structural elements, architectural design, and service space for installations. This approach reduces construction stages and limits material waste. It also removes the need for formwork, which can lower costs and reduce the environmental impact of temporary materials.

The entire house required around 39 m³ of concrete. The printer operated from 0.5 metres below ground level up to a height of seven metres.

Complex Architectural Geometry Through Robotic Construction

One advantage of 3D construction printing lies in its ability to produce complex curved forms. These shapes are difficult and costly to achieve with conventional formwork. The house follows a cave-inspired architectural concept with arches, curved walls, and a printed floor and roof slab. Several interior elements also use 3D printing to continue the flowing geometry inside the building.

During construction, the team added CNC-cut foam supports to create overhangs of up to 90 degrees. After printing, workers polished selected wall surfaces. This process produced a smooth, marble-like finish while keeping the layered texture visible.

In addition, full seismic compliance was confirmed under national building standards.

Designed For Seismic Resilience

Japan has some of the strictest earthquake-resistant building regulations in the world, which makes the approval of this project particularly significant. Engineers designed the house to comply fully with national seismic standards. The reinforced concrete structure, combined with precise robotic fabrication, ensures consistent structural quality and dimensional accuracy.

The printed walls and arches distribute structural loads efficiently, while the integrated wall system strengthens the overall stability of the building. By proving that a multi-storey 3D printed concrete structure can meet seismic requirements, the project demonstrates the potential of automated construction in regions that face frequent earthquakes.

Reducing Labour Pressure In Construction

The project also highlights how automation can help address labour shortages in the construction sector. Japan’s building industry faces increasing pressure due to an ageing workforce.

A four-person team operated the construction printer during the project. Robotic construction can therefore reduce the need for large teams of skilled workers. At the same time, it creates new roles such as robot operators, digital designers, programmers, and material specialists.

Towards Scalable 3D Printed Architecture

The successful approval of a two-storey 3D printed house shows that the technology can meet strict regulatory requirements. This milestone may open the door to wider applications. Future projects could include housing developments, disaster-resistant infrastructure, and rapid post-disaster construction.

For architects and designers, 3D printing offers new opportunities. The technology enables material-efficient construction, integrated building components, and greater design freedom.

As research and regulation continue to develop, robotic construction could become an important tool for faster, more efficient, and potentially lower-impact building methods.

Source: COBOD / ONOCOM
Photos: ONOCOM