Sustainability Through Biomimicry by Sebastian Chu

Sustainability Through Biomimicry Efficacy and Efficiency of Biomimicry for Sustainable Architectural Solutions

Student

Sebastian Chu

Student ID

490260175

Course

MARC6000 Thesis Studio

Tutor

Qianyi Lim

Coordinator

Chris Smith

ABSTRACT

Modern human beings are a sedentary indoor species. According to The National Human Activity Pattern Survey (NHAPS), humans spend approximately 87% of their lives within the confines of architectural constructs, 6% of their lives within motor vehicles and the remaining speck of time outdoors. 1 As a species that carries out a majority of daily activities indoors, humans can cause an inhabited building to impose significant impact on the natural environment.

Figure 1: Pie chart illustrating the average percentage of time people spent in various locations during the day. Sourced from: “The National Human Activity Pattern Survey (NHAPS): a Resource for Assessing Exposure to Environmental Pollutants,” Journal of Exposure Science & Environmental Epidemiology 11, no. 3 (2001): pp. 13-15.

1 Neil E. Klepeis et al., “The National Human Activity Pattern Survey (NHAPS): a Resource for Assessing Exposure to Environmental Pollutants,” Journal of Exposure Science & Environmental Epidemiology 11, no. 3 (2001): pp. 13-15.

Typically, in modern cities, architecture consumes a vast amount of energy due to not only the construction process, but also the maintenance and operation of a building during its lifetime. This can both directly and indirectly escalate into serious environmental issues on a global scale. 2 Due to this, sustainable design has risen to become a dominant leading practice in architecture and the built environment. Current sustainable approaches adopted by the building industry certainly work, but only to an extent. Environmentally conscious material choices by architects, manufacturers and suppliers can reduce environmental impact. Technological solutions can also increase the energy efficiency of buildings. 3 However, these conventional methods rely on the optimization of construction materials themselves, but material performance can only be pushed so far. Can architecture eventually become fully sustainable? If so, how can true sustainability be achieved? The current state of architecture in terms of sustainable architectural systems is not truly sustainable. As the architect Bill Reed put it quite ironically, the built environment could be “full of LEED platinum buildings and still destroy the planet.” 4 The architectural profession is reaching a stagnating point in terms of forcing buildings to continuously perform and respond better. The overshadowing issue with today’s thought process in regard to sustainability is that we are working backward, which is a hindrance to true sustainable design. In other words, buildings are made to be inherently bad for the

2 Yuta Uchiyama, Eduardo Blanco, and Ryo Kohsaka, “Application of Biomimetics to Architectural and Urban Design: A Review across Scales,” Sustainability 12, no. 23 (November 2020): pp. 1-16, 2. 3 Thomas Button, Biomimicry: A Source for Architectural Innovation in Existing Buildings (Rochester, New York: Rochester Institute of Technology, 2016), 11. 4 Salma Ashraf Saad El Ahmar, “Biomimicry as a Tool for Sustainable Architectural Design,” Towards Morphogenetic Architecture, January 2011, pp. 1-133, 21.

environment, and sustainability is currently focused on forcing improvements by lessening this impact through a myriad of solutions rather than redesigning the whole system holistically from the ground up. With this present struggle being a roadblock that prevents architecture from achieving true sustainability, recent decades have witnessed a shift toward a more novel approach. This approach is termed biomimicry, and it utilizes natural methods to mimic living organisms and the environment itself in an effort to further minimize the negative impact that architecture has on the environment. But why does this biologically inspired approach matter? Its significance lies in the fact that nature has the ability to provide optimal solutions selected over 3.8 billion years of natural evolution. 5 The living organisms and natural systems we currently observe in the environment is living proof of successful and highly optimized solutions. Architects should focus on studying these biomimetic solutions currently embodied in living organisms, and apply these lessons in design due to the potential to increase both the efficiency and efficacy of sustainable architectural systems. It is true that other biologically inspired concepts have existed in the past as well, but present-day biomimetic architecture differs in that it has developed rational methodologies and cumulative experiences which are able to bring new and innovative solutions. 6

Button, Biomimicry: A Source for Architectural Innovation in Existing Buildings, 13. Marwa N. Charkas, “Towards Environmentally Responsive Architecture: A Framework for Biomimic Design of Building's Skin,” Journal of Engineering Sciences 47, no. 3 (February 8, 2019): pp. 371-388, 372. 6

With the incessant attempts of today’s industries to seek more sustainable solutions and reduce environmental impact, time and resources are sometimes used counterproductively to develop unproven solutions. However, turning the focus on studying successful biological adaptations found in nature can certainly inform better designs in architecture. 7 Though a relatively new practice, biomimetic design in architecture has had its share of successful projects with time-tested solutions. In the heart of London’s main financial district, The Gherkin is a high-rise which adopts a biomimetic approach in the design of its structural system by mimicking the Venus’ flower basket, which has led to drastic reductions in energy expenditure in addition to benefits in performance in other aspects of the building. In Zimbabwe, the largest mixeduse complex named Eastgate Center applies a biomimetic solution inspired by African termite mounds to lessen energy consumption of the building as a whole. These projects at the forefront of biomimetic design argue strongly in favor of studying and adopting biological solutions to further improve the sustainability of buildings. There is an increasing sense of urgency for these types of biomimetic designs to be more widely adopted in sustainable architectural systems to push toward a higher degree of sustainability.

Button, Biomimicry: A Source for Architectural Innovation in Existing Buildings, 12.

BACKGROUND & INTRODUCTION

Figure 2: Timeline of the Earth versus recorded human history, Sourced from: Self-generated image, produced in Adobe Illustrator.

It is said that wisdom is widespread, not just limited in humans but also in the living organisms around us. The wisdom passed down from nature is much more diverse and complex than that of mankind, and has stood the test of time for far longer. As the Biomimicry Institute co-founder Janine Benyus explains, “If the age of the Earth were a calendar year and today were a breath before midnight on New Year’s Eve, we showed up a scant fifteen minutes ago, and all of recorded history has blinked by in the last sixty seconds.” 8 Scrutinizing nature from a biological and evolutionary lens, we begin to realize how well documented natural solutions are. Living organisms currently surviving

Janine M. Benyus, Biomimicry: Innovation Inspired by Nature (HarperCollins e-books, 2009), 17.

on the planet have endured innumerable filters in the environment over the course of many millennia, with these filters reshaping them generation by generation, and continuing to do so today. 9 In other words, survival of the fittest has driven unsuitable ones to perish, and the well adapted ones to thrive in the environments they inhabit, with the latter being most life forms that still exist around us today. As a side note, it is worth emphasizing that this discussion is inclusive of organisms which are invisible to the naked eye, not simply larger and more easily visible multicellular organisms. As human beings driven by our individual agendas, in the context of architecture and design we may refer to nature as a framework of continuous improvement that has a wide intellectual base, from which we are able to filter out excess information and hone in on specific methods related to our designs to achieve a higher level of understanding. 10 This method, biomimicry, has been defined differently by various individuals over different periods of time, so to avoid ambiguity it must be framed in a certain way. Biomimicry is generally recognized by the public as the use of actual living organisms or nature in design. This may cause confusion because there is a risk of individuals in unrelated fields to believe that mimicking nature is simply related to aesthetics. It is true that historically, designers have used nature as aesthetic inspiration for forms or decoration. However, the focus should be on functional solutions and not aesthetics. Researchers and practitioners in related fields have accepted the definition of biomimicry as the concept of mimicking biology and using nature as a model for design by studying

Ahmar, Towards Morphogenetic Architecture, 5. Ahmar, Towards Morphogenetic Architecture, 7.

and attempting to emulate it. 11 As an example, the British architect and biomimetic innovator Michael Pawlyn defines biomimicry as “design inspired by the way functional challenges have been solved in biology.” 12 Proponents of biomimicry hold on to the belief that biology is a great source to solutions that will eventually push mankind from an industrial era into an ecological era. Decades later, if biomimicry were to be seen as a revolution in retrospect, it would stand in stark comparison to the various industrial revolutions that have occurred in history. The “Biomimicry Revolution” would be the opposite of past industrial revolutions because it “introduces an era based not on what we can extract from nature, but on what we can learn from her.” 13

Figure 3: Changes in the role of Biomimetics from past to present, Sourced from: Self-generated image, produced in Adobe Illustrator.

11 12 13

Button, Biomimicry: A Source for Architectural Innovation in Existing Buildings, 14. Michael Pawlyn, Biomimicry in Architecture (London: RIBA Publishing, 2020), 147. Benyus, Biomimicry: Innovation Inspired by Nature, 23.

Throughout history, biomimicry has been called different names in different languages, and there is a lack of concrete documentation to pinpoint the origin of the concept itself. Moreover, the concept as we understand it today has also evolved considerably over time. From ancient civilizations such as Greece, designers have sought natural organisms as inspiration for perfect proportions that would become the classical ideal of beauty. These concepts inspired by nature include ones such as wholeness, integrity, unity and harmony. They are core concepts that Aristotle put forth, and form much of the Aristotelian view of life and art. 14 That may be considered a more primitive and unevolved form of the biomimicry we understand today. Moving forward, from available historical texts the first individual known to have experimented with the concept of biomimicry akin to the contemporary understanding, was none other than Leonardo Da Vinci himself. Da Vinci was likely the first individual to attempt an engineered approach to emulate the flight of birds. He attempted avian flight by creating mechanical contraptions, and even attached wings to one of his students for testing. Though his student eventually took off then crashed and broke his leg, this was a commendable approach and a first step toward intentional use of biomimicry for the advancement of mankind. 15 However, the origin of the actual word ‘biomimicry’ came much later, appearing in scientific literature in the early 1960s. Biomimicry may also be used interchangeably with the term ‘biomimetics,’ which was coined a decade prior by Otto Schmitt. 16 As a universally recognized example, famous modern architects such as Le

14 15 16

Ahmar, Towards Morphogenetic Architecture, 15. Martín-Palma Raul Jose and Akhlesh Lakhtakia, Engineered Biomimicry (Elsevier, 2013), 252. Pawlyn, Biomimicry in Architecture, 9.

Corbusier and Frank Lloyd Wright have put forth prominent writings related to biologically inspired ideas. Le Corbusier had even declared at one point that biology was ‘the great new word in architecture and planning’. 17 This shows that discourse and discussion regarding biomimicry and biologically inspired concepts have been in circulation in the field of architecture for many decades. Consolidating the changing role of biologically inspired design between the past and present, core differences can be identified, and by analyzing these differences we may begin to understand the importance of biomimicry at a deeper and more fundamental level. From previous description, the historic form of biomimicry – with Aristotle as the chosen example – was more superficial in a sense. It was mainly about borrowing natural forms and proportions for aesthetic purposes, and using those to shape the appearance of manmade designs. Over time, biomimicry has shifted away from aesthetics and leaned toward functional requirements. In the architecture profession, this change is born out of necessity. By dissecting, analyzing and re-applying functional solutions learned from living organisms and natural systems, there is potential to improve buildings in terms of increasing efficiency and reducing environmental impact. With that being said, there are various areas of sustainability which biomimicry can address in architectural design.

Ahmar, Towards Morphogenetic Architecture, 31.

Living organisms exist in a plethora of diverse forms, each embodying a different solution for us to decode. Some biological solutions that architects are able to extract from nature are viable only in specific situations, and can only be applied to the project at hand. This means that such solutions are unable to be easily adopted by a variety of architectural typologies. On the other hand, there are biological solutions that are both beneficial to sustainable architecture and also have the ability to be adopted by different typologies and across various project scales as well. The former category of biomimetic solutions has limited applications, while the latter is more versatile and will be the focus of this paper moving forward. The more widely applicable biological solutions are able to influence architectural systems as a whole rather than isolated parts, which grants the potential to positively impact sustainability on a greater scale.

DESIGN METHODOLOGY

Though we have spoken at length regarding the potential benefits of studying nature and extracting beneficial solutions to assist in the design of sustainable architectural systems, we must move from the theoretical into the practical and tangible aspects of biomimetics in architecture. In practice, the research and design methodologies for biomimetics are quite detailed, precise and well-illustrated processes. The distinctions between the various levels and sublevels of biomimicry are quite complex in nature as well, and require thorough identification and discussion for full comprehension. Beginning with the research and design methodology, two generally recognized and respected approaches currently exist. The first is the Problem-Based Approach, while the second is the Solution-Based Approach. Each approach has its distinct advantages and disadvantages, so usability and appropriateness highly depend on the design problem at hand. There are various analogies for the Problem-Based Approach in biomimetic design, but the most easily relatable one is termed the “Top-Down Approach” by Jean Knippers. This approach is one where architects and designers are first required to identify the initial goals and the parameters of design. Once the design problem has been identified, if in an interdisciplinary collaboration, the biologists must then seek solutions by attempting to match the design problems to organisms in nature that have resolved a similar issue in a biological way. 18 To explain this process in another way, after designers identify a

Ahmar, Towards Morphogenetic Architecture, 45.

problem that requires solving, they then “biologize” the problem at hand in order to better seek biological sources of inspiration. What this entails is that there is an abstraction that occurs during this process, in order to reframe the problem in broader and more widely applicable terms. These terms are then used to search for appropriate biological sources, from which principles and mechanisms applicable to the target problem can be neutrally extracted and applied so that the designer arrives at a trial solution that resolves the design problem. 19 This process, as illustrated by Michael Helms, Swaroop S. Vattam and Ashok K. Goel at the Design Intelligence Lab in the Georgia Institute of Technology, can be condensed into six steps which highlight the main components of the Problem-Based Approach in a linear fashion at first glance. The steps are as follows: Problem formulation, problem reframing, biological solution search, defining biological solution, principle extraction and principle application. Though on paper this six-step process appears to be linear, in practice it is not. The process is both non-linear and dynamic due to the fact that the outputs from the second stage onward are able to influence the previous stages, which can then constantly provide “iterative feedback and refinement loops.” 20 On the other hand, there is the Solution-Based Approach, which may also be called the “Bottom-Up Approach,” is essentially the opposite of its Problem-Based counterpart. Beginning with a biological source in nature that researchers are interested in, the source is then studied to a degree of detail where deep principles can be understood and

19 Swaroop S. Vattam, Michael E. Helms, and Ashok K. Goel, “A Content Account of Creative Analogies in Biologically Inspired Design,” Artificial Intelligence for Engineering Design, Analysis and Manufacturing 24, no. 4 (2010): pp. 467-481, 469. 20 Ahmar, Towards Morphogenetic Architecture, 10.

extracted for use. Subsequent to extraction, designers attempt to discover design problems in the built environment that the biological principles could be applied onto. 21 Rather than being simplified into six steps, the Solution-Based Approach is a seven-step process with an additional step starting with biological solution identification. The process is then as follows: define biological solution, principle extraction, reframe solution, problem search, problem definition and principle application. 22 Comparing the two processes, both actually end with principle application of the solution onto the design problem, so what really differs is the process.

Figure 4: Diagram illustrating the two conventional approaches to biomimetic design. Sourced from: Self-generated image, produced in Adobe Illustrator.

21 22

Vattam, “A Content Account of Creative Analogies in Biologically Inspired Design,” 470. Vattam, “A Content Account of Creative Analogies in Biologically Inspired Design,” 472.

With a clear understanding in terms of what the two standard biomimetic design processes are and how each of these processes are conducted, we now delve into the various levels and sublevels of biomimicry that can be studied and analyzed for different solutions to aid in resolving design problems in the built environment. According to Maibritt Pedersen Zari, when the current biomimetic technologies are examined, it can be observed that there are three distinct levels of biomimicry. In the order of small to large scale, these are the organism level, behavioral level and finally the ecosystem level. 23 It is crucial to identify distinctions and specific characteristics of each level, because the biological solutions that can be extracted from them differ to a significant degree, and the potential applications vary as well. In addition, each of these three levels possess five sublevels, or dimensions, which can act as appropriate and comparable analogies to pair with various aspects of a design or a building. These five dimensions are form, material, construction, process and function. The form of each level of biomimicry corresponds to what something in the built environment can visually look like. The material describes what the something is made out of. The construction explains how it is made. The process shows how something works. Finally, the function illustrates what it is able to do. 24

Maibritt Pedersen Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” Sustainable Building Conference (SB07), 2007, pp. 1-110, 4. Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 4.

Figure 5: Graphic representation of the three levels and five sub-levels of Biomimicry, Sourced from https://slideplayer.com/slide/4719723/

The lowest level of biomimicry, the organism level, is a fairly simple one to understand. At the organism level, biomimicry directly or indirectly copies the shape or form of a living organism. An industrial design example would be the commonly used Velcro which was originally inspired by the Bur flower. 25 However, the organism level has been criticized before for being less efficient, and solutions extracted from this level can potentially produce architecture that is either average or below average from a sustainability standpoint of view. This is because mimicking a living organism itself does not mimic “how it is able to participate in and contribute to the larger context of the

Amaresh Chakrabarti, Research into Design for a Connected World: Proceedings of ICoRD 2019 Volume 2 (Singapore: Springer Singapore, 2019), 424.

ecosystem it is in…because mimicking of organisms tends to be of a specific feature, rather than a whole system.” 26 This is especially true if compounding factors exist, such as instances where architects or designers who are not intrinsically familiar with the biological field attempt to imitate biological forms without a full grasp of how they function, such as at a cellular level. The second level of biomimicry is the behavioral level. At this level, biomimicry gains the potential to become more impactful in terms of improving the sustainability of architectural systems. The behavioral level attempts to mimic not the visual aspect of a living organism, but its behavioral aspect. 27 The ventilation system of the Eastgate Center, inspired by termite mounds, is an appropriate example which will be elaborated upon in a case study further into this research report. The behavioral level is more relatable to sustainable architecture due to the fact that organisms live alongside us, and therefore “encounter the same environmental conditions that humans do and need to solve similar issues that humans face.” 28 In other words, biomimicry at the behavioral level could yield more useful solutions that could positively assist in sustainable design. In architectural design studios, some tutors say that the more rules and limitations are imposed upon the student in the project brief, the easier it is to design architecture that is framed around those limitations. This is an appropriate analogy, and the same can be said about biomimicry. The environment or ecosystem that an organism survives in is much like the rules and limitations in a design brief. An environment possesses a carrying

26 27

Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 15. Chakrabarti, Research into Design for a Connected World, 424.

Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 6.

capacity, limited energy and limited materials. The environmental limits imposed upon an organism result in pressures which, over millennia, shape organisms in specific ways so that “not only well-adapted organisms continue to evolve, but also well-adapted organism behaviors and relationship patterns between organisms and species.” 29 With this understanding, it can be said that biomimicry at the behavioral level can extract biological solutions that are able to not only benefit sustainable architecture by reducing a building’s own environmental impact, but also potentially allow such buildings to function better alongside other architecture in either the nearby vicinity or the greater fabric of the built environment as a whole. Though there appear to be a host of benefits for biomimicry at the behavioral level, it is not without drawbacks. As Maibritt Pedersen Zari explains it, “Not all organisms exhibit behaviors that are suitable for humans to mimic and the danger exists that models of consumption or exploitation could be justified on the basis of how another species behaves.” 30 The final and highest level of biomimicry is the ecosystem level. Mimicking at this level pertains to the interaction and integration that a living organism has in the ecosystem. 31 In other words, the ecosystem level of biomimicry differs from the first and second levels in that it primarily is concerned with “the wellbeing of ecosystems and people, rather than ‘power, prestige or profit’.” 32 The ecosystem level may bear partial resemblance to the behavioral level due to the fact that biological solutions in the behavioral level also have the potential to be beneficial for ecosystems and people. However, at the behavioral

Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 14. Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 27. Chakrabarti, Research into Design for a Connected World, 429. 32 Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 35. 30 31

level, biological solutions are not primarily concerned with the betterment of the ecosystem or people. If this happens to be the case, then that is the result of the specific biological solution being selected by the designer for that purpose, rather than inherently bearing these beneficial characteristics, whereas biological solutions at the ecosystem level are inherently so. There is a lack of architectural examples in the current built environment designed in such a way that they adequately fit this level of biomimicry. However, in the field of waste water treatment, an appropriate example of ecosystem level biomimicry exists. Biolytix is an Australian developed system which “mimics soilbased decomposition to treat grey and black water and again integrates actual worms and soil microbes into the process.” 33 This is a complete example of ecosystem level biomimicry because the waste water treatment facility mimics how nature filters water in ecosystems as it sinks into soil and is filtered while draining through the various soil layers.

Figure 6: Biolytix biomimetic wastewater treatment diagram, Sourced from: www.biolytix.com/biopod/

Zari, “Biomimetic Approaches to Architectural Design for Increased Sustainability,” 71.

Case study: Eastgate Center

With a sufficient understanding now regarding the three levels of biomimicry as well as the two methods by which biomimetic design is typically conducted, successful biomimetic case studies can now be discussed and analyzed in terms of their efficacy and efficiency as sustainable architectural systems in the built environment. The first case study pertains to Harare’s Eastgate Center, widely recognized as a successful biomimetic building which was built as a shopping center and office block. Designed by Mick Pearce, Eastgate Center opened in 1996, becoming the largest building of its kind during that time with 5,600 sqm of retail space, 26,000 sqm of office space and 450 spaces for the parking lot. Though not the sole example of architecture that has been inspired by termites and the structures they live in, Eastgate Center is one of the earliest examples to have successfully adopted a biological solution from an ecosystem level to such a high degree, and is therefore the first of the two case studies to be discussed in detail here. Tasked with designing such a large complex and ventilating it, Mick Pearce sought inspiration from South African termites and the several meter tall termite mounds that they build. Before diving into the design of Eastgate Centre, the structure and organization of the South African termite mound must first be understood. The visible portion of a termite mound above ground is, in a sense, the tip of an iceberg. It is only a part of a larger subterranean system which is complex in the sense that the structure consists of nests, tunnel reticulum, surface conduits, chimneys, egress tunnels and other

structures. These integrated structures span both the mound aboveground as well as the nest underground. According to expert Scott Turner, the termite mound system is analogous of a lung, where the “multiple layers of subsidiary function are involved in the global function of colony gas exchange.” 34 To use the lung as a proper analogy, a brief but detailed description of the lung’s components and key functions will be provided. Physiologists say that the lung is a “multi-phase gas exchanger.” There are the upper airways of the lung, which mainly partake in gas exchange in the form of forced ventilation by forcing air in and out using the respiratory muscles of the body. However, deeper inside the lung’s passages, there are the alveoli and alveolar ducts which also partake in gas exchange, but through diffusion of oxygen from the fine bronchi and bronchioles into the bloodstream. Comparing this understanding of the lung to termite colonies and the mounds that they construct, there is a strong resemblance in functional organization. The parts of the termite mound that stretch all the way above ground can be compared to the upper airways of the lung, with both being in charge of gas exchange through direct ventilation of air with the external environment. The termites themselves can be likened to the alveoli deep inside the lungs, which are involved in gas exchange internally by absorbing the oxygen. 35

Scott Turner, “Beyond Biomimicry: What Termites Can Tell Us About Realizing The Living Building,” Proceedings of 1st International Conference on Industrialized, Intelligent Construction (I3CON), May 14, 2008, pp. 1-19, 16. Turner, “Beyond Biomimicry,” 8.

Figure 7: African Termite mound section illustration, Sourced from: https://www.youtube.com/watch?v=620omdSZzBs

Pulling back to look at the larger picture, we must ask, how can buildings function like termite mounds or lungs, and why do so in the first place? When we take into consideration the concept of the wall in architecture, we understand that walls are typically erected as barriers to create spaces. In other words, walls are used to create separation between the interior and the outside world, or to further create separation within interior spaces themselves. However, this is quite paradoxical in the sense that separation creates isolation, but spaces cannot be isolated if they are to be occupied by people. Therefore, according to Scott Turner, the way humans resolve this paradox is by forcing “building designs to include infrastructure – windows, fans, ducts, air conditioning, heating, etcetera – all essentially to undo what the erection of the walls did

in the first place.” 36 The study of living systems has taught us that living organisms are not exempt from this paradox. Organisms also create spaces frequently, and require walls to do so as well. However, instead of raising walls as barricades for blocking off the exterior and creating interior spaces, they treat walls as “adaptive interfaces” which manage the fluctuations of matter and energy through the walls themselves. 37 This type of environmental management by using walls as interfaces is evident in the mounds that termites construct, allowing them to collectively manage the internal conditions of their structures. Equipped with this information, one should arrive at the logical conclusion that by mimicking termite mounds at the behavioral level, architects could design more sustainable architectural systems by improving ventilation modeled based on that specific biological solution. The first human model of the termite mound was created by Martin Luscher, who devised a thermosiphon mechanism simulating how closed (capped chimney) termite mounds drive air ventilation. In this model, the termite colony produces 100 watts of heat in the lower nest underground, which buoys the heated air to drive it upward toward the mound and the surface of the ground. When the hotter air exchanges with the fresh air in the environment above, the colder and denser air is then forced downward back into the nest again to restart the cycle of air ventilation in a circular or cyclical air flow. 38 The second manmade model of the termite mound is one named induced flow, and it explains how open chimney mounds handle air circulation. Induced flow is familiar to us as the stack

36 37 38

Turner, “Beyond Biomimicry,” 12. Turner, “Beyond Biomimicry,” 12. Turner, “Beyond Biomimicry,” 2.

effect, where the top of tall structures are outlets that are exposed to faster wind velocities, drawing wind out while inlets at the ground level draws fresh air back into the bottom of the structure via a Venturi flow. In contrast to cyclical flow of the first capped chimney model, the flow of the open chimney model is unidirectional. 39

Figure 8: Perspective diagram illustrating Eastgate's ventilation system inspired by termite mounds, Sourced from: https://www.youtube.com/watch?v=620omdSZzBs

Turner, “Beyond Biomimicry,” 3.

Figure 9: Perspective diagram of active pumps for cool air circulation in offices, Sourced from: https://www.youtube.com/watch?v=620omdSZzBs

The ventilation design of Eastgate Centre is a combination of both principles, with each of the two models playing a role in facilitating the ventilation of the building’s air. Eastgate’s tall building stacks, paired with large air spaces that permeate the building, grant the potential for an induced flow effect. Moreover, the machinery and activities of human occupants in Eastgate Centre produce heat, which is stored inside the thermal mass of the building. This stored heat works in conjunction with the induced flow effect because it drives a thermosiphon flow from the office buildings and shops upward toward the higher levels and finally the roof, essentially allowing the induced flow effect to do its

job by exhausting the hot air and drawing fresh air from the lower levels. 40 This specific type of ventilation allows Eastgate Centre to achieve a relatively steady interior temperature without the implementation of active air conditioning throughout the whole building, greatly improving the sustainability of the building by reducing its environmental impact and energy expenditure. Although this appears impressive on paper, it is important to note that the design of Eastgate Centre’s ventilation system has some minor drawbacks. Although Eastgate’s ventilation system makes use of the building’s thermal capacity to hold heat throughout the day, the damping effect of the thermal mass diminishes over a longer period of time, meaning that it is possible to exceed the thermal capacity at times. Therefore, it was still necessary for Eastgate to install fans which pump air to actively drive airflow. During the day, low-capacity fans operate, but in the evening the high-capacity fans take over to extract the heat stored in Eastgate’s thermal mass in order to deplete it. Termite mounds require no active ventilation whatsoever to maintain the constant turnover of fresh air, so in this sense the biomimicry of the termite mound can be said to be a flawed solution when applied on the Eastgate Centre. Despite being an imperfect system because it is not completely passive, the biologically inspired solution for Eastgate Centre’s ventilation has undoubtedly reduced a significant degree of energy expenditure as well as eliminated the necessity for active air conditioning throughout the building, and is considered a successful case of biomimicry at the behavioral level.

Turner, “Beyond Biomimicry,” 13.

Case study: 30 St Mary Axe

In the heart of London’s financial district, 30 St Mary Axe (also known as “The Gherkin”) is a 41-storey high-rise office building designed by Foster + Partners in conjunction with Arup in 2003. The Gherkin is internationally recognized as an ambitiously designed building which, according to Foster + Partners themselves, possesses a system which “reduces the building’s reliance on air conditioning and together with other sustainable measures, means that it uses only half the energy consumed by a conventionally air-conditioned office tower.” 41 Being able to cut 50% of the energy expenditure of an office building is a massive feat, and The Gherkin is a prime example to have achieved this success through biomimicry at the organism level.

Figure 10: The Gherkin depicted next to the exoskeleton of the Venus' basket sea sponge, Sourced from: https://www.brunel.ac.uk/student-blog/Post?id=19a5411a-1d1e-415e-a43d-ae818a4bad5e

Foster + Partners, “30 St Mary Axe: Foster + Partners,” Offices and Headquarters | Foster + Partners, accessed May 21, 2021, https://www.fosterandpartners.com/projects/30-st-mary-axe/.

The organism that this building bears close resemblance to is the Venus’ flower basket sea sponge, otherwise known scientifically as Euplectella aspergillum (or E. aspergillum for short). In order to answer how The Gherkin achieved such a drastic reduction in energy consumption as well as a host of other architectural benefits as a result of its structural design, the structure and material composition of E. aspergillum must be analyzed and understood. E. aspergillum is a form of basket sea sponge due to the fact that it possesses a hollow, tubular structure akin to a basket, and this basket is supported by a lattice-like exoskeleton. Although visually appearing to be fragile, the sponge is composed of a self-made fiberglass material which is formed by extracting silicic acid from its seawater environment and then converting it into silica to grow its own structure. The sponge fashions six-pointed fiberglass structures, and these structures are organized vertically, horizontally and diagonally to form a skeleton structure. It is said that “this organic scaffold provides immense mechanical strength, enabling these sponges to live at depths of up to 1km.” 42 The silica material is then used by the sponge at the fiberglass connection points to reinforce and essentially bond the structure together as a flexible adhesive, allowing the whole fiberglass skeleton structure to flex and bend without damaging it. Being porous and mesh-like, E. aspergillum is also able to filter water with flagella lining the inner tubes by using a “motile force that draws water (and hence nutrients) in through the openings in the lattice.” 43 The deep underwater environment that the sponge resides in is subject to fast lateral currents, so it is interesting to note that the

Caroline Wood, “Imitating Life,” The Biologist (Royal Society of Biology), accessed May 13, 2021, https://heteaching.rsb.org.uk/biologistfeatures/imitating-life, 12. Wood, “Imitating Life,” 16.

cylindrical form of the lattice exoskeleton uses the rounded corners to disperse stresses created by lateral forces in its environment. 44 With a comprehensive understanding of E. aspergillum, familiar comparisons can be made to the structure of The Gherkin to understand how biomimicry has resulted in an efficient architectural form. The external superstructure of the building is composed of a steel diagrid structure coated with aluminum. This bears close resemblance to the hexagonal exoskeleton of the sponge with tubular structures. Formed into a tapering cylindrical shape, The Gherkin’s form results in several advantages. The exterior diagrid superstructure effectively carries the primary loads, allowing the floor plates to be free of columns for an open interior office plan. The cylindrical shape inspired by E. aspergillum also grants the freedom for the floor plates to be circular, and this has led to the design of 5-degree rotation between each floor plate, which allows for wedge shaped lightwells to be implemented. 45 Moreover, the tapering cylindrical minimizes windblast at the ground level due to wind being able to pass smoothly around it, so that pedestrians would be comfortable walking around the building without being buffeted by strong winds. Finally and most importantly, with the wind being able to pass by easily around the curved sides of the building, “its speed increases, causing a higher negative air potential at the back of the building. Architects…used this to drive a natural ventilation system.” 46 In other words, air passing around the building causes suction at the back, drawing air out of the tower at higher levels. To enhance the effectiveness of this, large vents were

44 Nkandu, Mwila Isabel, and Halil Zafer Alibaba. “Biomimicry as an Alternative Approach to Sustainability.” Architecture Research 8, no. 1 (2018): 1– 11, 4. 45 Nkandu, “Biomimicry as an Alternative Approach to Sustainability,” 5. 46 Nkandu, “Biomimicry as an Alternative Approach to Sustainability,” 11.

implemented at ground level to pump air upward, replacing the exhaust that has been sucked out of the building, thereby “reducing the need for air conditioning by 50%.” 47 Though not every advantageous aspect of The Gherkin has come about due to biomimicry of E. aspergillum, the clear similarities drawn between the building and its biological inspiration strongly suggest that this case of biomimicry at the organism level has enhanced the building’s structural efficiency and reduced its energy consumption to result in a more sustainable architectural system.

Figure 11: Illustrations and wind flow diagram depicting the effect of The Gherkin's circular form on wind speeds and ventilation, Sourced from: https://www.archdaily.com/447205/the-gherkin-how-london-s-famous-tower-leveraged-risk-and-became-an-icon-part-2

Wood, “Imitating Life,” 16.

Conclusion

Almost all buildings that currently exist in the built environment have had their share in contributing to negative environmental impact during their construction processes, and continue to do so while being inhabited and used by humans. In the present-day architecture profession, the standard approach when it comes to making a building more sustainable is essentially working backwards. We rely on the use of various methods to lessen the negative impact that a building otherwise would have upon the environment if no conventional sustainable design methods were applied to it. It is important to reiterate the point that it is becoming increasingly difficult to force buildings to continuously perform and respond better, because material technology can only be pushed so far, and the architecture profession will reach a stagnating point if it continues along this path. Sustainable architectural systems must be designed from the ground up, in conjunction with the construction of the whole building, and integrated as a core concept of the design. Yes, depending on complexity of the architecture that is being designed, it is possible to achieve a high degree of sustainability, with buildings designed for the Solar Decathlon project being several example proposals. However, with an increase in size and complexity of a building, it becomes significantly more difficult and time consuming to use conventional methods to create sustainable architectural systems that are integrated and a holistic part of the design. The argument here is that, by seeking external sources of inspiration and lessons from nature, architects are tapping into a vast database of highly efficient and viable solutions waiting to be studied, decoded and applied to the built

environment. To reiterate a point, there is certainly a sense of urgency that can be felt in the architecture profession, one which is asking architects to incorporate and adopt biomimetic designs on a wider scale in order to push for true sustainability. However, practical hindrances such as profit, adhering to the industry standard, fear of failure and the separation of nature and technology are some reasons why modeling entire systems using biomimetic principles remains a futuristic and impractical concept for most standard architectural practices. Even though a majority of the architecture profession currently adheres to conventional methods due to the aforementioned reasons, a minority of architects and designers willing to explore biomimetic principles as integral parts of their architecture and designs have proven the efficacy and efficiency of biomimicry on both the organism level and the behavioral level. With Mick Pearce’s Eastgate Centre mimicking the behavior of termite mounds to vastly improve passive ventilation of the building to the point of making active air conditioning unnecessary, it is undeniable that studying the behavior of living organisms has the potential to yield solutions applicable to architecture that improve sustainability by reducing energy consumption. With the design and completion of The Gherkin, Foster + Partners prove that mimicking the structure and composition of living organisms themselves has also proved fruitful in terms of inspiration for designing more efficient building structures, which in turn provide a host of benefits linked to sustainability. In terms of design methodology, Eastgate Centre would better fit the Solution-Based Method due to the functions and processes of termite mounds having been studied extensively by various researchers. The biological solutions extracted from

studying termite mounds were ready to be applied as a system to the building. On the other hand, the design process of The Gherkin would more closely resemble the ProblemBased Approach, where during the design of the 41-storey office tower, the problem of form finding arose, and the Venus’ basket sea sponge’s structure was studied to inspire the external superstructure of the building. It is an important point to note that, even though the biologically inspired case studies include examples that span across various biomimicry levels and both design methodologies, they are projects that incorporate biomimetic solutions that possess a greater potential to be implemented across a variety of projects. Earlier on in the paper, there was discussion pertaining to the differences in viability. Some biomimetic solutions are not as versatile due to being too project specific and unable to be applied across various scales and building typologies. Fortunately, the two case studies are exemplary in the sense that they illustrate biomimetic solutions which are both highly versatile in terms of being beneficial for sustainable design, as well as being widely applicable to other designs as well. These are the forms of biomimicry that the architecture profession needs to explore and begin to implement in the design of future buildings to push toward true sustainability in the built environment. From the primitive hut to the contemporary skyscraper, one of the most essential functions of a building has always been a barrier to act as a separation between man and nature. Buildings were designed to isolate humans, creating favorable interior conditions to shelter us from the elements as well as protect us against natural organisms that exist in the environment. This makes the separation of architecture and nature a view that comes easily and naturally to the mind. However, scrutinizing man and nature together through

a different lens provides an alternative view and understanding of our place, and the place that architecture sits, within nature. Notable architects and biologists have put forth the view that man and nature exist in a continuum, and that the concept of separation is unfounded. When we look to nature, we understand that natural evolution has resulted in a myriad of diverse organisms which possess their individual structures, intricate processes and complicated interactions within the environment. However, if humans look to ourselves, “ultimately, evolution is also the source for the human physiological-mental capacity and only from that could the idea of human technology even be conceived.” 48 In other words, when we view ourselves as products of natural evolution, which we undoubtedly are, then our mental capacity for intelligence which allows us to design architecture also stems from rather than being separate from it. By being willing to accept this world view, we can begin to accept biomimicry as a natural part of the design process, and seek natural inspiration to further improve sustainability in the built environment.

Pohl Göran and Werner Nachtigall, Biomimetics for Architecture & Design Nature - Analogies - Technology (Cham: Springer International Publishing, 2016), 8.

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