The construction industry heavily relies on finite resources and significantly impacts the environment through raw material extraction and waste generation. The ReSidence research demonstrator introduces a hybrid structural system that promotes a circular local bio-economy. By establishing closed material loops, the project addresses key challenges in the construction sector, reducing waste while extending the use of renewable materials. Enabled by digital design and fabrication technology the building system synergises the use of natural building materials such as flax fibres, willow, earth and timber to develop hybrid components, showcasing a future-oriented approach to sustainable building practices.

The project builds upon the combined expertise in sustainable construction at KIT, integrating seven KIT professorships, and the industrial partner FibR GmbH. This transformative project was showcased at the Landesgartenschau in Wangen im Allgäu.

Research Demonstrator at the Landesgartenschau in Wangen im Allgäu

​The ReSidence research demonstrator features a section of a multi-storey residential building, highlighting the use of natural materials combined with efficient, low-impact digital fabrication techniques. The project showcases the potential of prefabricated modular construction by combining digitally fabricated reinforced earth ceiling elements with a timber frame structure and a robotically woven flax façade system, all optimised for efficient material use and lean on-site assembly.

The materials used in ReSidence—earth, willow, flax and wood—were carefully selected for their sustainability and ability to promote closed material cycles, contributing to a local circular bioeconomy.

The unique integration of earth and willow enables the ceiling components to handle tensile forces through the willow reinforcement, while the earth works under compression, offering a sustainable alternative to steel-reinforced concrete elements.

Earth is infinitely recyclable without loss of properties and abundant globally, while willow, flax and wood are renewable plant-based resources that can be cultivated locally, promoting ecological and economic resilience with significantly lower CO₂ emissions compared to current construction practice.

Willow offers an additional ecological benefit: it thrives in soils saturated with water, making it a suitable crop for cultivation on rewetted moorlands in Germany. Previously drained moorlands have been significant sources of CO₂ emissions due to peat decomposition. Rewetting these areas, combined with cultivating willows, can help reduce CO₂ emissions by slowing peat decomposition and sequestering CO₂ through rapid plant growth while maintaining agricultural productivity.

By employing modular prefabrication, ReSidence minimises the environmental impact during production while significantly reducing noise and dust emissions on the construction site. This approach not only enhances construction quality but also mitigates disruption for local residents, demonstrating a commitment to community-friendly building practices. The modules can be dismantled and reused, ensuring that the material and building element cycles remain closed and eliminating waste disposal after the building is deconstructed.

Willow-Earth-Timber Construction System

Inspired by traditional half-timbered construction the modular ceiling elements developed for ReSidence are hybrid material components utilising the synergetic combination of willow, earth, and wood. In contrast to this historic reference, where willow and earth served as non-load-bearing infill materials, the digital construction methods developed within the ReSidence project enable a structural synergy of the compressive strength of earth with willow as tension reinforcement, creating a stable, load-bearing structure.

Research in digital construction technologies formed the foundation of the project, fostering innovation from initial concept to final fabrication. Digital tools played a crucial role in design exploration, structural simulations, and the advancement of construction techniques. This approach underscored the importance of synergetic research across digital and sustainable construction, building and structural design, component testing, and life cycle assessment. By integrating these fields, the project explored the interaction between materials and their potential for structural applications highlighting the project's commitment to transform sustainable building practices.

ReSidence showcases the potential of digital fabrication to overcome the challenges posed by low emissions processing of inhomogeneously grown plant-based building materials such as willow and flax though adaptive fabrication processes.

Willow branches are spliced into continuous macro-fibers and automatically arranged into spatial rebar structures using a custom developed digital prefabrication process. These tensile elements are filled with a earth-straw-reed mixture to provide compressive strength, thermal mass, and soundproofing—without relying on chemical additives or stabilizers.

The prefabricated components, measuring 3.6 meters by 1.2 meters, are dried, transported to the construction site, and assembled within the timber frame. Their modular design simplifies installation while enabling reuse, ensuring a closed material cycle that minimises waste.

This innovative approach addresses the inhomogeneity and unpredictable characteristics of plant-based materials, ensuring consistent quality and scalability. By replacing traditional craftsmanship with computational analyses and robust fabrication solutions, ReSidence paves the way for industrial-scale adoption of circular materials in construction, merging sustainability with structural performance.

The enclosure of the building displays a modular façade system supported by load bearing flax fibre composite elements, which are manufactured robotically. The robotically wound flax fibre filaments span the area between the primary load-bearing structure and carry the point-supported façade.

The hybrid earth-willow-timber ceiling components not only enhance the building's structural function but also introduce a distinctive architectural character that reflects a thoughtful integration of form and materiality. The combination of willow, earth, flax and wood demonstrates how challenges inherent to natural materials can be transformed into opportunities, empowering architects to actively shape and design change. These materials and the novel processes involved in their fabrication act as design drivers, inspiring new approaches to architecture that merge sustainability with design exploration. By embracing these emerging materials and methods, the repertoires of design and construction possibilities can expand, paving the way for creative, environmentally-conscious solutions that redefine the boundaries of architectural expression.

Professorship Digital Design and Fabrication (DDF)

TT-Prof. Moritz Dörstelmann, Javier Fuentes, Eszter Olah, Mehrdad Zareian, Carolin Feldmann, Daniel Fischer, Vincent Witt, Fanny Kranz

Professorship design of structures (dos)

Prof. Dr.-Ing. Riccardo La Magna, Christina Müller, Michael Kalkbrenner

Professorship Holzbau und Baukonstruktion + VAKA

Prof. Dr.-Ing. Philipp Dietsch, Christian Bertram

Research group Project and Resource Management of the Built Environment (IIP)

PD Dr.-Ing. Rebekka Volk, Simon Steffl

Professorship Bauphysik und Technischer Ausbau (bst)

Prof. Dr.-Ing. Andreas Wagner, Petra Mann

Institute of Concrete Structures and Building Materials (IMB) + MPA

Prof. Dr.-Ing. Frank Dehn, Agemar Manny, Lutz Gerlach.

Professorship of Design and Building Construction

Prof. Ludwig Wappner, Dr. Falk Schneemann

FIBR GMBH

Dr.-Ing. Julian Fial, Zirui Huang, Christian Dierk, Puree Srisuk

STIFTUNG NATURSCHUTZ PFRUNGER-BURGWEILER RIED

Christoph Schulz, Sabine Behr, Lisa Sander

The project was realised in collaboration with architecture students from the Faculty of Architecture at KIT: 

Annalena Thessmann, Kristof Kreer, Maximilian Granjon, Sydney Günther, Julia Centeno, Sean Ebner, Yaomin Lin, Homa Yazdi, Marion Baümgartner, Helena Krapp, Rebecca Steinbach, Lara Marquardt, Johanna Markus, Dorrin Abbassizadeh, Marie Walldorf, Luisa Estelmann, Montserrat Aravena.

Funding:

The project was funded by the Ministerium für Ernährung, Ländlichen Raum und Verbraucherschutz Baden-Württemberg within the Bioökonomie-Innovations- und Investitionsprogramm for the Ländlichen Raum (BIPL BW) Baden-Württemberg.