Green Buildings: From Nature-based Materials to Biomimetic Architectures
Lucy Zuo, Market Research Analyst at We Grow Green Tech
Constructing buildings accounted for 6.4% direct and 12% indirect GHG emissions in 2010. Global warming, energy efficiency, and embedded carbon dioxide emissions are factors that have facilitated the rapid market expansion of plant-based materials for buildings.
Renewable natural ingredients from algae and grasses can be converted into environmentally friendly construction materials with lower carbon footprints than their conventional counterparts. From using invasive Australian paperbark tea trees to derive concrete to generating insulated fibers from milkweed in dandelion, architects are constantly looking for sustainable building materials in nature. Plant-based building materials are increasingly being produced for their values in health and ecological sustainability.
Source: https://architizer.com/blog/practice/materials/5-bioplastics-to-build-with/
5 Examples of Unique Plant-based Building Materials:
I. Mycelium
The root structure of mushrooms called “mycelium” can be utilized to produce building materials stronger than concrete, more insulated than fiberglass, and are completely biodegradable. With a small carbon footprint, the mycelium grows underground without light and the need for external energy provision. Evocative is one of the first global companions to offer mycelium for building applications. It has created an eco-friendly insulation material that when injected into the walls of a building supports its structure.
BIOHM is also developing bio-based material for construction by repurposing waste. BIOHM produces bio-manufacturing material using organic and synthetic substrates to transform commercial and agricultural by-products from industries that would otherwise end up in a landfill. Mycelium insulation not only enhances the thermal capacity and acoustic absorption, surpassing the performance of other unsustainable materials in the market, including glass fiber and mineral wool. [2] Mycelium does not contain the synthetic resin-based materials that cause the harmful toxic smoke and quick spread of flames during a fire. Besides, shape, thermal and mechanical properties can be varied by sourcing different waste streams, providing a range of alternatives for insulation panels.
II. Bio-cement
Manufacturing of bricks adds up to about 12 percent of all carbon emissions by burning fossil fuels and calcination. Aiming to reduce carbon emissions in masonry manufacturing, bioMASON grows brick in its North Carolina factory in kiln-free, greenhouse-like conditions. Bacillus is a type of bacteria that has the property to naturally strain without genetic modification. Bacillus alters the pH balance of the surrounding aggregate material to allow calcium carbonate to grow and bind with little or no carbon emissions at room temperature. Bio-cement itself carries an off-white, almost translucent crystal texture, but under different weather conditions, the cement will display various colors and patterns.
III. Natural flax
Lingrove is a material and design firm that creates bio-composites from plant-based fibers and resins to replace traditional building materials and carbon fiber. EKOA® is Lingrove’s signature natural flax linen fiber with customizable shape, color, opacity, and fiber orientation.
Source: https://unreasonablegroup.com/companies/lingrove/
The company is committed to creating natural fibers that are high performing, durable, and carbon-negative. “Old-growth trees,” said Joseph Luttwak, Co-Founder and Chief Executive Officer of Lingrove, “like those native to California, are nature’s highest performance material and stronger than steel. These trees live hundreds, even thousands of years because they evolved to be a bug, rot, and notably fire-resistant. Only 10% of these forests remain globally. Due to the lack of supply, the market relies on lower quality farmed wood, plastics, concrete, and metals. Many of these substitutes are inferior, considered toxic, and account for 20% of greenhouse gas emissions. We reverse-engineer the superior qualities of old-growth wood using stronger-than-wood fibers and resins made of rapidly-renewable plants.”
IV. Structural Color
Apart from using plant-based ingredients in building material, some researchers have also experimented with mimicking structures of organisms to enhance the environmental sensitivity of buildings. Cell biologist Kaori Ihida-Stansbury is trying to incorporate structural color in building material to vary the opacity of the façade in response to the amount of light. Some examples of structural color can be found in the wings of the Blue Morpho butterfly and the feathers of hummingbirds. Inspired by the unique cellular behavior of structural color, eSKin team is interested in harnessing these material features and translating them into a scalable building with sensors that adapt to environmental cues to create a responsive feedback loop.
Source: http://www.achimmenges.net/?p=5612
V. Hygroscopic quality of wood
Wood’s sensitivity to moisture is usually considered as a challenge to structural stability, however, HygroSkin Meteorosensitive Pavilion ingeniously uses this hygroscopic characteristic to create apertures that respond dynamically to climatic changes. Most attempts in the past of creating environmentally responsive structures have heavily relied on energy-consuming mechanism superimposed on the building. The intrinsic dimensional instability of wood is employed to create a truly carbon-neutral architectural skin that is in constant feedback and interaction with its surroundings. [4] The opening of the pavilion consists of spruce cones that open when dried and closes when wet.
Source: http://www.achimmenges.net/?p=5612
Bio-based aggregates are generally highly porous with complex geometry that absorbs sounds and have hygro-thermal transferability. In contrast to conventional mineral-based cement and concretes, vegetal material has high flexibility and exhibits a non-fragile elastoplastic behavior that allows it to withstand mechanical stress. [5] The market of biodegradable building material is expanding, and along with increasing consumer tractions for green architecture, plant-based materials are becoming more cost-effective and accessible.
Bibliography:
1. buildings, P., 2020. Plant Based Buildings. [online] Living Environment Systems. Available at: <https://les.mitsubishielectric.co.uk/the-hub/plant-based-buildings> [Accessed 18 October 2020].
2. BIOHM, 2016. [online] Biohm.co.uk. Available at: <https://www.biohm.co.uk/mycelium> [Accessed 18 October 2020].
3. Journal. n.d. Inside The Weird Wide World Of Bioplastics: 5 Plant-Based Material Alternatives — Architizer Journal. [online] Available at: <https://architizer.com/blog/practice/materials/5-bioplastics-to-build-with/> [Accessed 16 October 2020].
4. Menges, A., 2013. Hygroskin: Meteorosensitive Pavilion | Achimmenges.Net. [online] Achimmenges.net. Available at: <http://www.achimmenges.net/?p=5612> [Accessed 9 October 2020].
5. Amziane, S. and Sonebi, M., 2016. [online] Pure.qub.ac.uk. Available at: <https://pure.qub.ac.uk/files/47919763/Overview_on_bio_based_building.pdf> [Accessed 4 October 2020].
