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Architects: IAAC - 3dPA
- Area: 120 m²
- Year: 2024
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Photographs:Iwan Baan
Text description provided by the architects. IAAC completed a 100 m² low carbon emissions building prototype using local soil and natural materials, utilizing the pioneering Crane WASP 3D printer. The 3D-Printed Earth Forest Campus in Collserola Natural Park (Barcelona) features enclosed, covered, and open spaces, serving as a live laboratory for testing new constructive and architectural solutions, and represents a significant step towards a sustainable km0 earth affordable housing model.
While the construction industry caters to 39% of the global CO2 emissions, various parts of the world are currently going through a housing shortage. After more than 10 years of research, IAAC and the Postgraduate in 3D Printing Architecture (3DPA) use a traditional material with cutting-edge technology to propose an affordable and sustainable housing solution.
The 3D-Printed Earth Forest Campus is an architectural intervention with several enclosed, covered, and open spaces made from 3D-printed earth that also serves as a live laboratory for the testing of new constructive and architectural solutions. The fragmented and deconstructed floorplan of the project exemplifies the potential flexibility in architectural design that the digital technology of 3D printing permits. The distribution has been evolving. Some wall sections were printed and torn down, only to be recycled into new walls and rooms. The organic spatial distribution of the project aims to create a multitude of rooms, perspectives, corners, and indoor, semi-indoor, and outdoor environments, the beginning of a labyrinth that distances itself from repetitive standardized contemporary architectural solutions, and demonstrates a high level of adaptation of buildings to their users’ needs.
The 3D-Printed Earth Forest Campus is constructed quasi-exclusively from natural materials. Below the ground, 50cm of natural stone foundation guarantees stability and drainage. Above, the first 30 cm of the wall consists of a solid 40-70 cm thick stabilized earth base, to protect from floods and rain. This base is cast into an earth-printed formwork, which was later reutilized for the printing of the walls. The earth walls are made from material sourced a few meters away: excavated from below 0,5m to avoid organic content, the earth is then dried in the sun, sieved to filter larger stones out, then mixed with water, added organic fiber and natural enzyme until finally pressed into the 3D printer. The wall is printed at a rate of 25 cm height per day, to avoid collapse due to self-weight, and can reach a total of 2,5m in approximately 10 days. When partially dried, the roofs are installed: they both rest and are anchored to the earth walls to avoid uplift due to wind forces. In some cases, the connection to the timber roof was post-tensioned with steel cables down to the foundations.
The walls of the Campus take advantage of 3D printing, a digital technology that enables a high level of customization in design. Depending on their position within the project, the walls combine different performances: structural, holding their weight and their roofs (potentially used in multi-story buildings), thermal barriers and humidity regulators, or they frame small openings for light and views but also controlled natural ventilation.
Contrasting to typical masonry and earth construction, the printed walls frame cavities that make them 50% hollow. These cavities can serve for reducing the material use, but also the integration of insulation, services, and natural ventilation of the walls. The wall thickness varies from 70 to 40 cm according to how much load they need to carry and their orientation: how much they need to protect from solar radiation.
Earth as a material has relatively low mechanical strength, used with traditional techniques (rammed earth or compressed earth blocks) it mostly leads to walls being thick and opaque. The walls of this project seek a certain lightness and light porosity made possible by the construction technique, depositing layers one at a time, and creating small local cantilevers into a network of 20 cm wide openings.
This ongoing project has reached a crucial milestone by demonstrating the construction of multi-climatic environments with the 3D printing of intelligent performative walls from local earth, a step closer to a carbon-neutral architecture adapted to its users and environment.
