Introduction
In the face of intensifying urbanization and the climate crisis, how can a paradigm shift in architecture, guided by the principles of building metabolism theory, offer a sustainable and regenerative solution to address the challenges of our rapidly evolving urban environments?
Abstract
In an era of intense urbanization there is an imperative need for new sustainable architectural paradigms. This research delves into the innovative intersection of building metabolism theory and sustainability, employing a metaphorical lens to explore architectural designs inspired by the intricacies of natural systems. Central to this proposal is the incorporation of living elements, including algae, lichen, and water capture, to create a holistic and regenerative architectural ecosystem.
System Metaphor: unified relation between environment and human through architecture Inputs/ Organs Microalgae, lichen, bed reeds and water capture serve as key inputs, symbolizing the foundational elements of a sustainable building metabolism. Microalgae, housed in bioreactors, harness sunlight to produce biomass and thermal energy. Lichen, integrated into building surfaces, acts as both a bioindicator of air quality and an aesthetic. addition. Water capture technologies ensure efficient utilization of a precious resource.
Methods
Building metabolism unfolds as a dynamic process mirroring the cycles of nature. Microalgae not only contribute biomass but also offer a renewable source for biogas production. The resulting CH4 fuels electricity generation, setting the stage for a self-sustaining energy loop. Lichen, with its air-purifying capabilities, further enhances the environmental quality within the built space. Water captured is judiciously utilized for irrigation in a vertical farming system, creating a harmonious synergy among these sustainable processes.
Lichen
Lichen is one of the oldest living things and its production is a result of the symbiosis between fungi and algae. [1]. Lichens consist of an algal body attached to fungal filaments (hyphae). Figure [1] shows the agreement of mutual benefit – algae generate energy while the hyphae holds the algae, protects it and supplies minerals. [2] Lichen draws its nutrients from air and rain.
Current research on the field highlights the potential of a new type of green facade which is based on allowing lichen to grow on it. Bio-receptive concrete facades have been in the central point of the investigations as they allow lichen to grow on it utilizing its advantages rather than it being an indicator of decay. Lichen improves air quality as it filters the air naturally, it captures pollutants from the atmosphere such as nitrogen oxides and particulate matter. [4]
Although there have been several environmental benefits, lichen has been viewed as a negative phenomenon. This essay is investigating the integration of lichen with bio receptive facade material in the design to create a more sustainable and green approach in AEC industry. Concrete is well known for it durability as well as for its large CO2 emissions. Specifically for the 8% of the global CO2 come from concrete. [5] Allowing plant growth on these facades is a literal way to balance the CO2 emissions. Bio receptive concrete is a more sustainable version of this material and could be applied to existing buildings as well as a second skin. By using the photosynthesis process, these small non-vascular plants can take in up to 3.9 billion metric tons of carbon per year his facade system requires no external irrigation or maintenance facilities,
unlike the typical green wall systems. [7]
Microalgae Panels
Algae, is a type of seaweed that uses sunlight through the photosynthesis process to capture CO2 either from water or from air and release O2. Every pound of algae biomass cuts off 1.8 pounds of CO2. Although algae represent only 0.5% of total plant biomass, they produce about 60% to more than 75% of the oxygen needed for humans and animals on earth. In the process of absorbing carbon and releasing oxygen, algae produce green bioenergy and nutritious protein[8]. Turning our focus into the bio-algae interactive facade we investigate ways of incorporating specially designed modules, housing resilient algae, chosen to flourish in a unique man made environment. These algae serve a dual purpose: enhancing the visual appeal of the facade and contributing to the building’s energy dynamics. Through photosynthesis, the algae convert sunlight into energy, potentially powering various building functions. The facade becomes a living canvas, responding to environmental factors such as sunlight and temperature by changing colors and patterns dynamically. Beyond aesthetics, the algae play a role in air purification, absorbing carbon dioxide and releasing oxygen through photosynthesis. This natural process contributes to improving air quality around the building. Additionally, the algae act as a natural shading which helps in temperature regulation within the building and reduces the need for excessive heating or cooling. Which can provide up to 50% or more of the building’s
energy consumption [9].
Outputs
The culmination of these processes yields a community-centric vision. Vertical farming emerges as a source of fresh produce, addressing local food security. Simultaneously, the generation of electricity and the purification of air contribute to enhanced living conditions. The community becomes an active participant in the building metabolism, fostering a sense of shared responsibility for sustainability.
Conclusion
Building metabolism theory, when integrated with sustainable practices inspired by nature, transforms architectural landscapes into living entities. The metaphorical
incorporation of microalgae, lichen, and water capture not only enhances energy efficiency and air quality but also cultivates a communal ethos. This essay proposes vision where buildings are not static structures but dynamic contributors to the well-being of the community, embodying a sustainable and regenerative future.
Bibliography
[1] Pawlyn, M., Biomimicry in Architecture, Riba Publishing: London, 2011
[2] Selim, S.E., A study mimicking fungus and lichen mechanisms to achieve thermal comfort in buildings
[3] Yosemite. (Yosemite Online Library), http://www.yosemite.ca.us/library/
[4] Greaver, T., McDow, S., Synthesis of lichen response to gaseous nitrogen: Ammonia versus nitrogen dioxide
[5] Lehne, J.; Preston, F. Making Concrete Change. Innovation in Low-Carbon Cement and Concrete; Chatham House, The Royal Institute of International Affairs: Cambridge, UK, 2018.
[6] Kazi, F., Prieto, A., Ottele, M., The Role of Geometry on a Self-Sustaining Bio-Receptive Concrete Panel for Facade Application
[7] Bornschlegl, S., Krause, P., Cordula, K., Leinstner, P., Analysis of the Microclimatic and Biodiversity-Enhancing Functions of a Living Wall Prototype for More-than-Human Conviviality in Cities
[8] Ghada Mohammad Elrayies, (2018), Microalgae: Prospects for greener future buildings, Renewable and Sustainable Energy Reviews, Volume 81, Part 1, Pages 1175-1191, ISSN 1364 0321,https://doi.org/10.1016/j.rser.2017.08.032
[9] Hanafi, Walaa, (2021), Bio-algae: a study of an interactive facade for commercial buildings in populated cities. Journal of Engineering and Applied Science, 68. 10.1186/s44147-021-00037-5
