3BUILD: 3D printing in construction

3BUILD

Design and development of a novel large-scale 3D printer for concrete buildings and infrastructure

3BUILD developed a lightweight, portable robotic mortar printer for buildings and infrastructure, bringing large-scale 3D printing in construction from laboratory trials to a full-scale demonstrator. The project concluded with the construction of the first 3D-printed house in Greece at the TITAN Elefsina Plant.

Partners

National Technical University of Athens
TITAN Cement Company SA
Sika Hellas ABEE
COS Hellas LTD

Total Budget

€906,734

Duration

July 2018 – December 2022

Demonstrator

First 3D-printed house in Greece, built at the TITAN Elefsina Plant with 22 hours of printing over three days.

Funding

“Research-Create-Innovate” action of the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (EPAnEK) within the NSRF 2014-2020, co-financed by Greece and the European Regional Development Fund.

Researchers

Vasilios Spitas, Georgios Vasileiou, Nikolaos Katsiotis, Christos Kalligeros, Konstantinos Tsioumanis

Principal Investigator

Vasilios Spitas

Contact Person

Christos Kalligeros
ckalligeros@mail.ntua.gr

Publication

Katsiotis M. et al. (2023). 3BUILD – First 3D Printed Structure in Greece. In International RILEM Conference on Synergising Expertise towards Sustainability and Robustness of Cement-based Materials and Concrete Structures (pp. 673-682). Springer Nature Switzerland. https://doi.org/10.1007/978-3-031-33187-9_62

Extra Links

3BUILD good practice profile

The 3BUILD team in front of the first 3D-printed house made in Greece, built at the TITAN Elefsina Plant.

Full-scale gantry printer before and after the construction process.

Scope

The scope of 3BUILD was to design, develop and validate a novel large-scale 3D printing system for constructing concrete buildings and structural components. The project combined printer architecture, printable cementitious materials, automation, prototype construction and structural validation into one integrated construction workflow.

The work moved deliberately from controlled laboratory development to full-scale demonstration. Small and half-scale prototypes helped the team refine printing parameters and material behavior, while the final full-scale printer proved that the approach could be deployed on an industrial site and used to produce a real building envelope.

Mechanical design of a full-scale robotic mortar printer.
Development of specialized printable mortars and process parameters.
CAD/CAM and CNC-like automation for controlled deposition.
Experimental validation of printed components, including structural and seismic performance considerations.

Timelapse from the construction of the first 3D-printed house in Greece.

First in Greece Full-scale 3D-printed house built at the TITAN Elefsina Plant.

Only 22 printing hours The demonstrator was printed over three consecutive days.

~80 m² target Printer architecture sized for a complete house-scale application.

Modular gantry Portable structure designed for fast assembly and site adaptation.

Impact

3BUILD brought 3D printing in construction beyond small-scale laboratory applications and into a full-scale building demonstration. The project targeted faster and more automated construction, reduced labor-intensive site operations, lower material waste and greater freedom to create geometries that are difficult or costly with conventional formwork.

The combination of a deployable robotic printer and tailored printable mortars is especially relevant for construction in remote or challenging locations, including islands and mountainous regions. At the same time, the project kept structural reliability at the center of the work, linking digital construction methods with mechanical performance, seismic requirements and practical site constraints.

Interior rooms formed by the 3BUILD 3D printing process — Printed room layout produced during the full-scale construction demonstration.

MD-Lab’s Contribution

Mechanical design of a deployable construction printer

MD-Lab was responsible for the detailed engineering design, analysis and optimization of the full-scale 3D printing system. The lab defined the printer architecture, its major subsystems and its operational principles, translating the project requirements into a gantry-type machine that could position the printing head precisely over large construction areas.

The full-scale concept used four support pillars and an X-Y motion stage, with a modular structural layout intended for transport, rapid assembly and adaptation to different construction sites. This modularity was one of the key practical contributions of the design, because construction-scale 3D printing needs machinery that can be deployed without becoming a permanent factory installation.

Comparison between the digital 3BUILD design and the constructed 3D-printed building — From digital design to constructed 3D-printed geometry.

Prototype pathway and experimental validation

The project advanced through a sequence of prototypes. At NTUA, a half-scale 3D printer enabled the team to optimize printing parameters, validate deposition behavior and evaluate the mechanical performance of printed mortar under realistic conditions. The half-scale printer remains part of MD-Lab’s research infrastructure, with the ability to build structures of approximately 2 m x 2 m in plan and up to 3 m in height.

Experimental testing connected the construction process to engineering performance. Printed material specimens and structural components were investigated so that the final demonstrator would be supported by data, not only by successful fabrication.

MD-Lab half-scale 3D printer used for 3BUILD prototype development — MD-Lab’s half-scale printer used to refine the printing process before full-scale deployment.

Two-meter-high 3D printed structure produced with the MD-Lab half-scale printer — First 3D-printed structure reaching a height of 2 m, produced using MD-Lab’s half-scale printer.

Experimental testing of 3D printed cementitious material specimens — Experimental investigation of the mechanical properties of printed cementitious materials.

Full-Scale Demonstration

The final printer was constructed and installed at TITAN’s Elefsina Plant, where it produced the first 3D-printed house in Greece. The printed structure reached a height of 2.6 m, with a total printing time of 22 hours distributed over three days. The demonstrator showed that the 3BUILD system could move from design intent to an industrial construction environment while preserving the precision and continuity required by robotic mortar deposition.