Earthen vault house
The earthen vault house is an upscale Dutch holiday home, that takes advantage of the potential afforded by robotic fabrication for earth construction. The project aims to demonstrate the advantages and possibilities of digital design and fabrication, combined with building sustainably with earth. Terrestrial is exploring this concept, by developing material, technology and process. In support of this effort, Summum Engineering collaborated with starting designer Jung Ghim on the design of the conceptual house, with funding from the Creative Industries Fund’s Building Talent program.
By 2050, the Dutch construction sector must be circular and emit about 95% less greenhouse gases compared to 1990. At the same time, 75,000 homes must be built each year in order to house one million more households in 2050. Construction is responsible for 50% of our raw material consumption and 37% of our waste. The vast majority of this is concrete and brick that is ground up into rubble for road construction. Dutch housing construction still relies heavily on these materials, which together account for about 12% of our total CO₂ emissions.
Could concrete and brick, heavily favored in Dutch residential construction, be replaced by earth, a locally available and abundant resource?
Compressed earth is a sustainable and low CO₂ building material consisting of sand, clay and gravel, sometimes with lime or cement, and has a centuries-old tradition worldwide. However, typical construction methods are time-consuming and, like concrete, still require formwork. Through the robotic spraying of earth, this construction process can be automated and highly accurate, while opening up entirely new possibilities for freeform design.
This concept is being explored by Terrestrial, by developing material, technology and process. This project, funded by the Creative Industries Fund, aims to imagine what a robotically fabricated earthen house could look like.
As a showcase, an upscale Dutch holiday house was designed that takes full advantage of the freeform possibilities enabled by the earth-spraying robot. The challenge was to visualize the economic and environmental benefits of digital fabrication and earthen construction with an appealing and sculptural form.
However, such shapes may not appear financially competitive and carry the added risk of the technology being pigeonholed, capable only of a particular type of aesthetic. The strategy became to inform the design with traditional stone, brick and earthen vaulting techniques, and marrying those with conventional building components and materials.
The end result is heavily inspired by thin-tile Catalan vaults, that, like earth, are made of brittle material that prefer to work in compression. Modern structures and techniques to design and build them have been explored in recent years by the Block Research Group (BRG) at ETH Zurich and others around the world, like the 2013 Bricktopia project by Map13 in Barcelona, Spain.
Geometry and stereotomy
The layout of the house was found through parametric modeling to intuitively find the right proportions within fixed constraints such as the width of openings, the footprint of the house and individual rooms, and angle of the walls. This layout then formed the boundary conditions to create the main vaulted roof.
This shape was generated by using the BRG’s RhinoVAULT software, which uses a type of graphic statics (thrust network analysis) to intuitively create and explore compression-only structures. The resulting vaulted form was cut into large earthen blocks, or voussoirs, that can be made with robotic earth spraying. Starting from the large outer frames as supports, these blocks are arranged and assembled at an angle, with each course of blocks, resting against the previous one – a technique referred to as Nubian vaulting found in Egypt, as shown above. As the voussoirs meet at the top, they form a herringbone pattern, similarly seen in Mexican vaulting, yet another historical technique.
The warm atmosphere, exuded by the curvatures of the earthen vault, envelops the main living spaces, allowing unobstructed flow and views throughout the ground floor. Private spaces such as the bath- and bedrooms are situated below on the basement floor. Both levels are connected through the central spiral staircase which also lets more light into these living areas.
A unique characteristic of the house is that, unlike typical vaults, the openings are rectangular, gradually transitioning into arched form, leaving creases that blend the hard edges into a smooth surface. The custom frames serve as a rigid keystone, allowing for the rest of the vault to be compression-only, or funicular.
The vault drops down into the basement floor, creating an intermediate space between the floors for the staircase while functioning as the structural support. Each bedroom has a private, terraced courtyard that extends and connects to the base of the rectangular openings on the upper level.
The early stages of design consisted of many formal experimentations, to think of aesthetics derived from the capability of the robotic spraying. Abstract models, sketches, paper and clay models were made to spark ideas. A site visit to a Dutch holiday park was used to grasp this part of Dutch recreational culture and to identify key design factors and requirements.
A program of demands was defined to facilitate design choices, which included site conditions, family types to host, surface areas for the rooms and living spaces, vault type, construction method, and some aesthetic preferences. Based on these constraints, layout variations were created, and once settled, the project followed a linear trajectory of development where details were increasingly refined.
The project was a collaboration between a starting designer, Jung Ghim, and a senior designer, Diederik Veenendaal of Summum, as part of the Creative Industries Fund’s Building Talent program. This program is intended to stimulate the exchange of ideas and knowledge between established and starting designers and makers within the creative industry, and to strengthen the connection of starters to the professional field. The collaborative programme offers the opportunity to connect and create room for in-depth research and experimentation.
The design was developed with input and feedback from Jelle Feringa of Terrestrial. Additional design critics, Florian Idenburg and Edyta Augustynowicz, were invited to comment on iterations of the design.
The earthen vault house showcases the formal advantages of robotic spraying, and stresses how earth – a most abundant and sustainable material – could regain its economical competitiveness with the aid of parametric modeling and automated construction. Robotization allows us to approach the built environment in a very different way, and to respond to design factors that are locally relevant. Instead of allowing mass production to determine the design, mass customization makes it possible to respond to local needs and thus achieve a sophisticated design.
Jung Ghim | gyul (starting designer)
Diederik Veenendaal | Summum (senior designer)
Jelle Feringa | Terrestrial
Robert Verbeek | Summum
Creative Industries Fund (Building Talent 2022)