This exhibition shows ongoing research focussed on developing a novel approach of digital toolmaking for extruding cob – a ubiquitous and ancient building material.  

Cob is a simple mixture of subsoil and fibre – usually straw or hay. Cob is a basic, natural bio-composite that has been used for millennia in traditional house building in many cultures around the world. It has one of the lowest environmental impacts of any house building material and the emerging climate crisis provides a strong rationale for the material to be revalued.  

This project takes a new approach, instead of utilising digital and robotic technologies for direct cob or earth building, it seeks to use new technologies in toolmaking scenarios with a focus on profile extrusion as the production approach and has developed specific geometries for the extrusion profiles (dies) that work very well with cob mixtures and can be produced by cheap, consumer level 3D printers. 

Initial experiments focused on extruding the cob material into interlocking wet brick units that facilities rapid construction of cob structures. The use of digital fabrication technologies to create the extrusion dies to produce interlocking extruded elements means that cob construction can be done at a fast pace and with new customised cob mixtures that meets the contemporary requirement for building performance in aspects such as thermal and structural applications.  

The aim of the project is to contribute to the development of building components for low carbon construction. A key objective is to present a blueprint for a complete fabrication system that enable researchers, architects and builders to utilize digital tools to experiment with extrusion profiles for new cob construction approaches and adobe brick design at incredibly low-cost, unprecedented speed and with almost no environmental impact.