- Living materials for construction
- 3D-printing structures from raw earth
- Building from mushrooms
- Managing Sick Building Syndrome
- Programming bacteria to grow building materials organically
Construction is currently one of least sustainable industries on the planet, and is responsible for approximately half of all consumption of non-renewable materials. Buildings also disturb natural environments, and often contribute significantly to pollution long after their construction is complete. Some studies even suggest that the construction industry is responsible for around half of climate destruction overall. However, there is hope – there have been notable advances in technology and building design in recent years. These changes could potentially be a turning point for the sustainability of the construction industry as a whole, and allow us to live more harmoniously with nature.
Living materials for construction
Most buildings are currently constructed – predominantly or entirely – from non-renewable materials. However, the concept of living materials for construction shows promise in enabling sustainable development. Living materials are materials which replicate functions of living organisms, such as being able to grow, self-heal, and self-replicate. What’s more, these materials can eventually return to the ground after their purpose has been served. In some cases, living materials are made up of living matter like bacteria. Some scientists have even built bricks from photosynthetic cyanobacteria, the marine bacteria synechococcus, or E.coli which, believe it or not, can be safe and useful for this purpose.
3D-printing structures from raw earth
Israel-based construction and development company Rogovin has invested in ecological innovation in various projects, including a project called ‘To Grow a Building’. This innovative construction project was presented in an outdoor lab space during Jerusalem Design Week 2022. The project involves a custom-made “robotic arm” that is controlled by a computer programmed with digital workflows, and used to build small constructions from seeds and soil. These materials are ‘planted’ in layers using 3D-printing technology. Once construction is completed by the robot, structures continue to grow in the typical manner of these materials – vegetation grows, and roots embed themselves into the earth.
“The project constitutes a portal into a future world where some people will build buildings, and others will grow them… It is a custom-made machine that can execute a complex task: 3D printing of a structure composed of seeds and soil… Upon completion of the printing task, the structure receives a life of its own: the seeds sprout, the walls are adorned with a green facade, while on the inside they fill with dry roots – a new and strong material in itself. Instead of buildings made of concrete and steel, the project suggests an architecture that uses local soil and roots as structural elements.”Promotional material for Jerusalem Design Week 2022
Rogovin is not the only company investing in 3D-printing technology for living building materials. Italy-based firms Mario Cucinella Architects and the 3D-printing company Wasp have completed construction of an entire house printed from raw earth. The process that they have developed for this is known as TECLA – or technology and clay. The TECLA model uses research on vernacular construction (or the use of only locally-sourced materials) and bioclimatic principles, aimed at reducing wasted resources. TECLA uses a similar process to the ‘To Grow a Building’ project, printing raw earth, soil, and seeds as a composite building material. The use of sustainable, locally-sourced materials makes this a promising example of low-carbon construction, and represents a potentially huge step towards transforming the construction industry into a more environmentally-friendly one.
Building from mushrooms
In addition to using soil, seeds, and earth for construction, fungi are also being explored as a building material. A type of fungal matter called mycelium has proven to be biodegradable as well as extremely durable, and has been tested already in some construction projects. Mycelia can grow into a wide variety of shapes and structures depending on the conditions, which makes them particularly useful for building projects. A collaboration between design firm Arup Group and architect David Benjamin saw a 40-foot-tall pavilion constructed in New York from bricks made of a composite of mycelium and corn husks. As well as producing no waste (in fact, this process could even recycle existing agricultural waste) or emissions, these bricks are sturdy and lightweight. With over one-and-a-half million known species of fungi, the full potential of mycelium for construction could be immense.
Another New-York-based firm, Ecovative, uses mycelium to replace materials like plastic and styrofoam for product packaging. This caught the attention of Harris Wang, associate professor of systems biology and pathology and cell biology at Columbia University Irving Medical Center. Wang wondered if a similar method could be used to create a living material, and requested that Ecovative send him products from their factory without having carried out their usual procedure of sterilising their materials. Wang believed that the self-healing and self-fusing properties of fungus would make it ideal as a biodegradable construction material. A four-year collaboration between Wang and Damen Schaak, Ecovative’s principal scientist, led to the development of fungal-composite blocks, bricks, and boxes similar in consistency and functionality to Styrofoam. Like Ecovative’s existing products, these were sustainable and designed to biodegrade after use, although they also had the capacity to continue to grow and change over time and in response to external stimuli. One of the most interesting findings was that the bricks could be programmed to produce and receive molecular signals that enable them to sense pollutants (for example, cholera and carbon monoxide) and even communicate with each other.
Managing Sick Building Syndrome
As we spend more and more of our time indoors, we become more susceptible to a condition known as Sick Building Syndrome. Sick Building Syndrome refers to a collection of symptoms that are directly linked to being inside a particular building, and generally dissipate at some point after the sufferer has left the building. Common symptoms include respiratory problems, nausea, irritation of the throat or skin, and even cognitive issues. Sick Building Syndrome can be caused by any number of issues with construction, such as inadequate ventilation, contamination from vapour intrusion, and harmful building materials. An extreme yet widely-known case of a building material causing health issues is asbestos, which was used widely in construction until the late 20th century, when its harmful effects became widely-publicised. Although asbestos has been phased out in most parts of the world, other harmful substances can still be used, and the hazards of commonly-used materials may be yet to be discovered. Transitioning to the use of organic materials, such as soil and raw earth, for construction could alleviate many cases of Sick Building Syndrome – after all, materials like raw earth have been used for many centuries, and exist around us constantly.
Programming bacteria to grow building materials organically
In many ways, buildings are structured similarly to living organisms – they have external structures to protect their internal processes, they use energy and regulate their temperature, and they also create waste. Ineffective building design can lead to processes being thrown ‘out of balance’ – for example, if ventilation is poor, temperature and air flow cannot be controlled. The use of living materials for construction furthers this idea of a building being comparable to a living organism, and enables the optimisation of a building’s overall ‘health’, as well as that of its occupants. A team of researchers from the University of Colorado Boulder has developed products like algae-based concrete, which they believe could be used to construct carbon-free and even carbon-negative buildings that can repair themselves and adapt to their environments. The university’s Living Materials Laboratory uses “synthetic biology toolkits to engineer bacteria to create useful minerals and polymers and form them into living building blocks that could, one day, bring buildings to life.” For example, cyanobacteria – or green, algae-like microorganisms that commonly grow in fish tanks – were used to produce a ‘biocement’ which combined with sand to create a “living brick”.
“By keeping the cyanobacteria alive, we were able to manufacture building materials exponentially. We took one living brick, split it in half and grew two full bricks from the halves. The two full bricks grew into four, and four grew into eight. Instead of creating one brick at a time, we harnessed the exponential growth of bacteria to grow many bricks at once – demonstrating a brand new method of manufacturing materials.”Wil Srubar, Assistant Professor of Architectural Engineering and Materials Science, University of Colorado Boulder
Another company that has been using biocement is US firm Biomason, which has made strides in sustainable construction practices. Using a manufacturing process from Delft University of Technology that 3D-prints living bacteria into layered structures, Biomason creates biocemented blocks and tiles. Unlike more traditional methods of manufacturing cement, which require burning fossil fuels to extremely high temperatures and make up approximately 8 per cent of global carbon emissions, biocement can be produced at room temperature. Biomason has also used funding from the US Department of Defense to create biocement that can be used underwater, such as in seawalls. This self-healing material can use calcium and carbon from seawater to repair cracks. While existing examples of this in use are limited, the technology shows great promise.
The field of living materials for construction is a very recent development, and we have barely begun to scratch the surface of what may be possible with these methods and technologies. There are challenges to be overcome before these methods can become commercially viable on a large scale. These challenges include costs, the need for safety testing, the potential for biocontamination, and entrenched attitudes about living matter. Many in construction associate living organisms with mold, pests, weeds, and other things considered undesirable. However, living materials also represent the hope that a highly unsustainable industry could be transformed into one that not only reduces environmental damage, but could potentially even reverse it.