Earth and Digital | 1

Earth and Digital

Research on the design and fabrication of the Free-Form Earth Constructions

Report by Zubin Khabazi

While world’s contemporary architecture has been vastly affected by the notion of computation and

its consequences in digital design and fabrication, it seems that there are various techniques of

design and related materiality which are mostly spreading across the globe. This is happening

because of the fact that new technological advancements in architecture are using predefined

materials and techniques and not yet adapted with the older techniques of construction and their

materiality which were been in use in the building industry for decades, sometimes centuries.

Among them is the idea of working with earth construction in this contemporary realm of digital

design and facing such complex notion of mixing these two not-well-matching phenomena of earth

and digital.

Digital architecture has been extensively coupled with digital fabrication technologies in which the

use of machineries like CNC becomes common. These machines forced designers to use certain sets

of techniques and related material systems, mostly flat-sheet materials to suit the needs and

necessities of such machineries. The fact that working with digital code in order to make something

is so promising, that for a while pushed most of the architects, exploring it with lots of products

made by sheet materials, cutting based fabrication and almost similar assembly logics. But building

industry is more diverse in terms of material logics and could not be limited with some special

techniques and materials just because of the early understandings of the machine qualities. The idea

behind this research agenda is that to find out potentials of working with earth, yet using the

beneficial qualities of digital design and fabrication technologies. The question is, while it seems that

both earth materials and techniques of construction, and also digital architecture, have lots of

potentials, where are the areas that these two can mix and match and create unexpected outputs

which could extend the current available catalogue of material practice in contemporary

architecture.

The general research hypothesis is that the earth could be a great source for materiality in

contemporary architecture and can play an important role in the realization of modern designs if

well understood and constructed. While it has been in use for several centuries, from the ancient

civilizations, to the traditional masterpieces, it could also be a great source for today’s products. This

research investigates various ideas to utilize high potentials of the earth materials and construction

techniques, the methodology of combining them with recent technological advancements in digital,

and related aspects of such hybridization.

In terms of the methodology of the work, there are distinctive areas to focus on, each reflects one of

the main important aspect of the whole research agenda. The main challenges for the research at

the moment are Free-Form Earth Construction using various techniques and in different scales, Pre-

FAB Earth Construction either off or on-site, Earth 3D Printing and all related structural, material and

technical explorations, analysis and implementation in design process. While these challenges and

related methodological approaches are the subject of the research of a big group of experts engaged

in the global research agenda, the rest of the report will focus on the Free-Form Earth construction

techniques, being developed as part of the AA_Lyon Visiting School in Les Grands Ateliers, France.

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Free-Form Earth Construction

Beauty and complexity of free-form design products attracted architects to design their projects in

this fashion and digital design tools enabled them to do it far more easier than conventional

techniques. While free-form and flexible surfaces are now available as design tools in software

packages and related techniques of fabrication develop quickly, it seems really challenging to design

such products with earth. If succeeded, the method would bring new potentials for the construction

of such geometries to the spectrum of digital design.

Mud is great to make compressive structures. Traditionally, it has been used to make structures

which can bear compressive forces, but as other masonry structures, they are not really good at

dealing with tension forces. This has limited the possible geometries made with earth, to those

which usually transform compressive forces easily to the ground. It also caused such structures to be

thick and with lots of excess material. The idea of designing free-form surfaces initially mean that the

product should deal with bending moments, continuous change of compression and tension forces

while traversing inside a complex geometry. This challenge needs lots of intelligence to be imbed in

the design of such projects.

During two successive AA Visiting Schools in Lyon, France, the agenda of making free-form earth

construction was one of the main research fields. In the first version in 2013, the team focused on

the development of digital techniques which could be used as a medium to design products like a

generic shell. This shell then could be converted into a fabric formwork to be covered with mud.

Removing the digitally fabricated formwork, the output was a shell made out of thin layer of earth. It

was important to interlink the qualities of the shell and its material behaviour to the digital design to

make sure that the output of digital process, performs well in reality. This has been done through

lots of experimentations and studies. The second version of the school in 2014 focused on larger

scale prototypes to make sure that this idea of digital design would match the real physical

construction when scale plays an important role. Other parameters like cantilevering and mud

layering has been tested in parallel. It was important to observe and understand the behaviour

because earth materials are not simply scalable. After these first two periods of study and

observations, it is clear that design and construction of such geometries with earth has lots of

potentials but with certain considerations and need different researches and experimentations in

various fields which are listed here.

- Design and Fabrication of Free-Form Structures

Designing free-from surfaces becomes easy by using various tools, developed in software packages.

Using NURBS technology or various Mesh editing software and plug-ins would make it easy to deal

with the design side. There are various techniques to fabricate such surfaces with digital techniques

by using CNC machines or Robotic arms depending on the material which is going to be used. But the

challenge arises when such designs are going to be made by mud. Here is the point where constrains

and limitations should be implemented in the design process. This has been explored in physical

experimentations and related digital model makings through two AA visiting school programs in

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Lyon. In later stages, it would be possible to design various products while the material behaviour is

embedded in digital models, proves whether it is possible to be built or not. This could be further

completed into digital toolset, plug-in or add-on for the design, analysis and fabrication of such earth

constructions which needs researches in multiple fields.

- Structural properties

While thinking about free-form earth construction, structural properties of the design become a

driving factor for the realization of the project. The fact that earth constructions are generally

heavier than similar geometrical products, makes such concerns more important in the design and

analysis of them. The way force vectors travel in the system should be carefully analysed and the

design should be optimized or become intelligent for dealing with them. There are number of tools

to analyse the material properties of earth and its related structural behaviour with techniques like

FEM which are available in design software and plug-ins today. This area of the research needs

collaboration with the engineers and experts in related fields and careful laboratory observations

and tests at later stages.

- Earth as a basic material for Free-Form Construction

There are various earth mixtures which could serve as the basic material for the construction of free-

from surfaces. There are extra materials like fibres which should be carefully understood and

implemented into the system for the success of the construction. Various techniques of layering,

mixtures of materials, timing and other related issues have been tested in experimentations in two

AA visiting schools but still need more documentations and research in parallel to the other parts of

the global research agenda. Catalogue of material possibilities would help the more successful

production of the design, in various scenarios or different geometrical situations. Partners like

CRATerre would be great assets for further collaborations in this area of the research.

- Material Behaviour of Earth in Free-Form Geometries

After design and realization of each project, it would be valuable to further analyse the output and

gather the feedback in order to address the failures or successes in each step and to well document

the pros and cons. This has been done by visually documenting the project’s process but still needs

more elaborate measurements and analysis. This might be more precise if accomplished in

collaboration with engineering partners in terms of structural behaviour of the product, or earth

experts to check out the material properties. Defining such feedback loops would enrich the design

principles and would affect the whole process.

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Fig.1. Sample modelling of the fabric formwork experimented in digital and physical for further

explorations on the design capabilities of the free-form earth constructions. AA Lyon Visiting School,

Les Grands Ateliers, France, 2014.

Fig.2. Transforming digital into physical, by Cutting and setting up the fabric formwork for applying

various layers of the earth.

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fig.3. Final Free-Form structure made by a thin layer of earth as a self-stable structure.

Outlook

Application of earth construction in contemporary architecture still needs lots of further researches

as outlined in this report, yet the qualities of material that has been observed in the early steps

proved that earth has lots of potentials in this realm. Although there are various lines of research in

the global research agenda, this single task of making free-from earth construction by itself would

propose couple of parallel researches for the development of design and fabrication tools, structural

analysis and material properties. The driving force behind all of these researches is that earth

architecture could bring us sustainability, thermal insulation, on-site material and community work

and more, as it was played such roles in the history. This research would try to bring these valuable

parameters to the contemporary architecture by using it in a contemporary fashion through usage of

all related technologies to serve for the better future of the built environment.