3dPA Forest Campus: Pioneering 3D-Printed Earth Architecture in Spain

Nestled in the heart of Collserola Natural Park, Barcelona, the 3dPA Forest Campus by IAAC - 3dPA represents a groundbreaking leap in sustainable architecture and 3D printing technology. Completed in 2024, this 120 m² pavilion prototype demonstrates how low-carbon construction, local earth materials, and digital fabrication can converge to create an innovative, affordable, and environmentally conscious building solution.

Sustainable 3D Printing with Local Earth

The 3D-Printed Earth Forest Campus was built using locally sourced soil, natural fibers, and enzymes, combined with the Crane WASP 3D printer, a pioneering tool in additive construction. This low-emission, km0 construction approach minimizes transportation impact while promoting circular construction practices.

IAAC’s research, conducted over more than a decade through its Postgraduate in 3D Printing Architecture (3DPA) program, addresses two pressing global challenges: the construction industry’s 39% contribution to global CO2 emissions and the worldwide housing shortage. By integrating traditional earth techniques with cutting-edge 3D printing, the project proposes a scalable model for affordable, sustainable housing.

Architecture as a Living Laboratory

The Forest Campus is designed not just as a building but as a live laboratory for exploring new architectural solutions. Its floor plan is intentionally fragmented and deconstructed, allowing walls to be printed, recycled, and reconfigured into new spaces. The result is a flexible spatial organization, featuring enclosed, semi-indoor, and outdoor environments.

This organic layout fosters multiple perspectives, corners, and pathways, creating a labyrinthine yet intuitive architecture. Unlike repetitive, standardized contemporary buildings, the campus adapts seamlessly to the needs of its users, exemplifying the potential of 3D printing in architectural design.

Intelligent Wall Systems and Performative Design

A core innovation of the project lies in the 3D-printed earth walls, which combine structural support, thermal insulation, humidity regulation, and natural ventilation. The walls are partially hollow—up to 50%—allowing for reduced material usage, integration of insulation, and enhanced airflow.

• Foundation: 50 cm of natural stone ensures stability and proper drainage.
• Base walls: A 30 cm-thick stabilized earth layer protects against flooding and rain.
• Printing process: Walls are printed at 25 cm per day, reaching 2.5 m in about 10 days. Roofs are then anchored to the walls using timber and, in some cases, post-tensioned steel cables for wind resistance.

The walls vary from 40 to 70 cm in thickness depending on load, solar exposure, and orientation. They feature a network of 20 cm openings that create lightness, porosity, and cantilevered forms, demonstrating how earth architecture can achieve both aesthetic beauty and functional performance.

Towards Carbon-Neutral, Adaptive Architecture

This innovative campus demonstrates the potential of multi-climatic environments through intelligent 3D-printed walls, establishing a milestone in carbon-neutral construction. By leveraging local resources, reducing emissions, and embracing adaptive, user-focused design, the 3dPA Forest Campus sets a precedent for future sustainable housing solutions globally.

This project illustrates that earth-based 3D printing is not only environmentally responsible but also capable of delivering customized, resilient, and spatially rich architecture. It marks a pivotal step toward affordable, low-carbon, and adaptable housing models for communities worldwide.

Key Features

• Location: Cerdanyola del Vallès, Spain
• Architects: IAAC - 3dPA
• Area: 120 m²
• Year: 2024
• Construction: 3D-printed earth, natural fibers, low-carbon materials
• Function: Live laboratory, sustainable pavilion, housing prototype

All photographs are works of  Iwan Baan