A proposed approach to environmental sustainability regarding the technical design of structures.
Throughout history, the human race has had to live symbiotically with nature, depending on natural resources for survival. A myriad of structures from the past can be found exemplifying intuitive solutions that work alongside nature. In these examples the structural form of a dwelling has evolved to be highly efficient within its specific environment.
An example of sustainable structural efficiency which has continued to be used for centuries is the Inuit’s igloo. The ancient craft of building has been passed down through the generations, utilising the specific environmental conditions and that can be fully constructed in half an hour. For instance, compacted, dry snow is required for the snow blocks to be individually structurally stable, thereby yielding a warm protective dwelling with light able to permeate through. The wind-blown snow used naturally welds together, interlocking the ice crystals. The form active structure of an igloo is based on the catenary curve, creating an optimised shape helping ease tension within the blocks and direct loading down the sides of the igloo rather than through the centre. For this reason, upper ceiling blocks are wedged in place more for shelter than structural support.
Figure 1 – Inuit family building an igloo, from Wikimedia
Dating as far back as Ancient Greece, mathematicians Pythagoras and Euclid recognised the presence of the ‘golden ratio’ in a plethora of natural scenarios. This has since been applied to the engineering of many structures including the proportions of the columned façade and plan of the Parthenon, one of the most influential precedents for the development of Western Architecture. Due to its non-form-active arrangement an excess of stone is used reducing the overall efficiency of the structure, furthermore, all material above the architrave is ornamental and non-structural. Having said this, the chosen structural system positively contributes to the architectural treatment, with high structural efficiency beneath the architrave.
Figure 2 - Caryatids of The Erechtheion, Athens, Greece, 420BC, from Chegg
Similarly, the natural world has always been a source of aesthetic inspiration for engineers, designers and inventors. The use of caryatid statues as structural columns in the Erechtheion incorporates art, science, nature and mathematics in one single form and stands as an example of structure as ornament. The organic theme has continued to influence modern architecture and can be misinterpreted by the untrained eye as ‘eco-design’ or ‘biomimicry’ when in fact these are little more than stylistic explorations of the natural world.
Sustainability is commonly defined as “the ability to be maintained at a certain level”. This maintenance is relevant to multiple aspects of sustainability namely economic, environmental and social. Due to the interrelated nature of these, it is important to consider all of them for true environmental sustainability to not only be achieved but also maintained. According to the Brundtland Report of 1987, a more relevant definition of sustainable development is “development that meets the needs of the present without compromising the ability of future generations to meet their own needs”.
We are currently in the midst of an environmental crisis where the construction industry alone produces over one third of CO2 emissions. Looking at the current state of climate change it is clear drastic changes need to be made regarding how architectural practice is conducted. As depicted in Figure 3, if we continue along our current trajectory without following our recommended environmental policies will cause an increase in temperature anywhere between 4.1 and 4.8°C above the pre-industrial temperature. This temperature increase would give rise to further levels of extreme weather patterns and as a result, the extinction of the human species.
Figure 3 - 2100 Warming Projections, from Climate Action Tracker
In order to reduce the damage greenhouse gas emissions have had on our environment ‘regenerative architecture’ needs to be implemented. This encourages the representation of a truly sustainable system as a closed-loop system, where there is no net waste of resources as the system replenishes itself automatically. This is referred to as ‘regenerative architecture’ and some definitive changes need to be made in our approach to architectural design and construction for this to be fostered. The cultivation of regenerative architecture takes time which is extremely scarce. In the meantime, alternate approaches need to be taken before it is possible to fully transition to a closed-loop system.
It was only after the industrial age that architecture grew into its own discipline separate from structural engineering. The turn of the 20th century brought with it the discovery of the energy stored in fossil fuels, the availability of new building materials and advanced techniques. Suddenly it was possible to directly control the thermal temperature with indoor heating and electricity, enabling the use of thinner walls and a larger amount of glass. This made space for the creative freedom of the architect resulting in the emergence of a variety of experimental styles, most of which lacked efficiency and environmental sustainability.
In reaction to the dominating style of Neoclassicism prevalent at the end of the 19th century, natural forms began to infiltrate into mainstream design. Through the utilisation of newfound resources, construction became a lot more affordable, opening up the experience of a refined lifestyle to the middle-class. The addition of ornamentation and detailing became almost common practice while it had previously been reserved for the upper class. Art Nouveau was a prime example of the incorporation of natural shapes and patterns into an architectural style.
Figure 4 – Horta House, Brussels, Victor Horta, 1898, from Apollo Magazine
Through the incorporation of asymmetrical lines, vines and flowers, Victor Horta’s home and studio, Horta House, elegantly transforms seemingly crude natural materials into the elegant features on the exterior and interior of the building. This gives the structure a light ethereal feeling which was previously not possible to attain with traditional construction methods. Figure 4 shows the glass atrium above the stairwell incorporating ‘American glass’ and stained-glass windows for diffusion of the light. The non-form-active cast iron framework is also visible.
However, this aesthetic harmony comes at a cost to the environment. Cast iron, marble and stained-glass all have extremely high embodied energy and carbon generated during quarrying and production. There is also an excessive use of iron for decorative features rather than structural elements. A similar effect could’ve been made using wood, heavily reducing the carbon footprint of the building.
Figure 5 – Structural framework of the Riverside Museum, Glasgow, Zaha Hadid, 2011, from Archiscene
Early modernism was a major initial influential style in which the architectural attitude shifted to an ethos of “human superiority over the natural world”. This mindset only increased the polarity between architecture and sustainable development, paving the way for the creation of impressive structures often monumental in size and hence, extremely inefficient in their structural form. A large proportion of construction occurring in the 21st century continues the legacy of modernism, liberating architecture from the constraints of the past through cheap fossil fuels.
Figure 6 – Riverside Museum interior, from AR
Designers didn’t appreciate the extent of damage these processes were having on the environment and instead were glorified for the feats of creative genius. Since high quality structural engineering is paramount for the working of each structure, the factors that are not taken into account inevitably ended up being cost and environmental damage.
Zaha Hadid’s Riverside Museum in Glasgow serves as example of an architect’s complete disregard for the structure of a building and the complex engineering required to bring it to life. This open plan gallery space, constructed in 2011, showcases typical inconsideration of structural requirements through design for artistic purposes.
From an environmental perspective the rigidity of Hadid’s vision meant that there was no way for the building to be engineered in an efficient form. Since this non-form-active steel structure consists of long-span triangular girders, either columns or transverse elements were required to support the loading from the roof structure. However, due to the function of the interior as a gallery space, columns were not an option.
Hadid also rejected the idea of connecting the girders to create a structural framework at either end, resulting in extremely high internal forces. This meant an extremely large volume of steel needed to be used in order to carry the loading within the portal frames to the ground.
Overall, an astoundingly low regard for environmental sustainability has been taken, especially considering how recently this building was constructed. In terms of the innovative engineering conducted by Buro Happold, this project was a roaring success. Intuitive design on the other hand is lacking, with little sympathy to the natural environment which has become a requirement for architecture in the modern age.
Figure 7 – Bloomberg Building (cross section), London, Foster & Partners, 2017, from AR
The issue of ‘greenwashing’ in current sustainable architecture is growing exceedingly problematic. Misinformation to the general public and practicing architects has a detrimental effect on the advancement of environmentally sustainable design, setting us back from meeting 2050 sustainability targets, and prevents truly skilled eco-designers from receiving the recognition they deserve. This is the issue with the Bloomberg building in London which managed to receive a BREEAM score of 98.5%, which later increased to 99.1%, while being predominantly constructed from concrete, steel and glass. This was done through the incorporation of eco-gadgets like the intelligent wall consisting of light and heat sensitive vanes that orient themselves for maximum thermal and solar efficiency.
Architect Foster & Partners and structural engineer AKTII won the 2018 RIBA Stirling Prize for architectural excellence proving, in the eyes of George Kafka, author of the Architectural Review, that “Money talks”. Inferring their win was largely due to the fact that the total building cost was over £1billion. Further commentary from the February 2019 ‘Failure’ issue includes the statement, “Bloomberg London’s innovation in its operational sustainability is an effective greenwashing of the company’s substantial contribution to the very engine room of climate destruction”.
In order to maintain environmental sustainability, social and economic sustainability also require a significant amount of attention. Since true sustainability is represented by a closed loop system the weakening of any aspect results in the eventual failure of the whole system.
This is one of the many reasons why the preservation of existing historical buildings is very important. A large part of history and culture is tied up in buildings that are knocked down every day. This results in an extreme waste of energy and materials, along with the release of further greenhouse gases through the decommissioning and rebuilding process. Structures now need to be designed with adaptive reuse in mind so that future reconstruction seamlessly integrates into the design process. If this became common practice it would have a hugely beneficial effect both economically and environmentally.
Figure 8 – 171 Collins Street, Melbourne, Bates Smart, 2011, from AR
171 Collins Street in Melbourne, Australia has served many functions over the past 100 years. Bates Smart Architects were chosen to transform the structure into a working office building. Rather than implementing sustainable features into a historic building, this project directly expands the structure through the addition of the glass skyscraper. Bypassing a lot of complications with regard to the interaction with the pre-existing structure during feature installation.
Upon closer inspection, however, it soon becomes apparent that this is yet another example of unsustainable greenwashing through the overuse of sophisticated systems to achieve high energy scores and make up for the colossal structure they “attached” onto the back. This project received a 6 Star Green Office rating and are proud bearers of the “World leadership” level for environmental sustainability.
Since skyscrapers on average use 30% more energy than standard buildings, attaching a fully double-glazed glass skyscraper is extremely inefficient. Architect Ken Yeang has noted that many designers incorrectly assume the more eco-gadgets are used, the more ecological a design is. Furthermore, architects often knowingly add these features so that they can continue producing self-satisfying building designs leaving the ignorant public under a false sense of security. When in reality the structurally inefficient form may completely negate from the benefits.
Arguably the most influential architect within the field of environmental sustainability is Ken Yeang, who has based his practical philosophy off of the self-sustaining nature of ecosystems. The emulation and replication of ecosystems within our cities is not a new idea however it had not successfully been put into practice before the emergence of Yeang’s architecture. Yeang recognises that the use of skyscrapers is, in itself, extremely bad for the environment. However, since they are going to be built regardless in areas of high population density, designing them so that they are sympathetic to the environment can be extremely useful both for maintaining social sustainability and environmental sustainability.
Yeang identified that although ecosystems include both abiotic and biotic factors, the overwhelming majority of architecture is created solely with abiotic factors and challenged this in his architectural endeavours. The range of biodiversity was also an important consideration as this greatly strengthens the ecosystem. Determining the exact location of target species habitats is conducted before the determination of the structural form.
Figure 9 - The Solaris Building, Singapore, Ken Yeang, 2011, from e-architect
Both of these considerations among many others are demonstrated through his Solaris Building in Singapore. Situated in a former military base area, this is the first eco-design skyscraper to successfully replace the lost biodiversity of it’s environment. The incorporation of a continuous 1500m perimeter ramp supports the biodiversity of the building, balancing abiotic and biotic factors.
Sitting on a two-way spanning reinforced concrete slab meant that this non-form-active structure was relatively easy to mould into a bespoke plan structure as required in this building. Although the embodied energy due to the use of concrete is fairly high, it is significantly less than if the structural component of the skyscraper was steel or glass.
Another environmental benefit was the incorporation of passive airflow and ventilation throughout the building. This is made possible through the inclusion of a passively ventilated glass atrium, situated in the centre of the tower, this centralises and distributes both airflow and natural light through the different rooms of the structure.
An important aspect of sustainable architecture is integration into the natural environment. This was first stylistically explored by Frank Lloyd Wright in the 1930’s. As the pioneer of Organicism, he introduced a new design philosophy, “the rejection of tradition”. This enabled nature inspired design to break away from the visual rigidity of curved shapes, focusing on the materiality of the structure. Wrights most renowned project, Fallingwater, is an example of a structure that is extremely well-integrated into the natural environment aesthetically. The drawback, however, is prevalent in the inefficient use of materials. Structure is navigated by aesthetic design rather than environmental sustainability or material efficiency leading to huge wastage in material. This can be prevented through the incorporation of biomorphic structural design.
Figure 10 – Model of the Biorock Pavilion, Michael Pawlyn, from Dezeen
After the rise and fall of modernism and full acceptance of the need for a change in approach to structural design, architects and engineers must look to innovative, integrated solutions for this complex issue. Researchers exploring biomorphic structures have found that a state of compromise can be attained in the way technical design is approached. It is possible to mimic the mathematical patterns and sequences that give rise to highly optimised and efficient structures naturally occurring in nature. Biology tells us that lightweight flexible and adaptable structures are highly efficient and so basing designs on these principles will increase a buildings functionality making it an ideal candidate for adaptive reuse.
Explorative architect Michael Pawlyn, a prominent figure in regenerative design and biomimicry, is currently working on the ‘Biorock Pavilion’ project to build an extremely efficient, carbon sequestering structure using the absolute minimum volume of material. The building methodology of this project is still in its early stages of development but is planning to be created within seawater, utilising the minerals available to create its structural form, producing a material similar to reinforced concrete. A thin steel framework will act as a guide for the form-active pavilion shape, based on the golden ratio and other mathematical patterns prevalent in shell structures.
Previous work Pawlyn has been involved in includes The Eden Project, a visitor’s attraction greenhouse centre, inspired by the design of bubbles, situated in a former clay mine location. The structure is a form-active, lightweight steel superstructure with large plastic hexagonal pillows forming the external envelope allowing a large amount of light to penetrate in. The superstructure is so light that it weighs less than the air inside the biome. Because of this, the foundations could be made much smaller than previously expected, further saving on material.
Figure 11 – The Eden Project Biomes, Cornwall, Grimshaw Architects, 2000, from edenproject.com
In order to reach environmental sustainability, the natural environment needs to be restored to a healthy level. This can only be done through the continual support of ecosystems and biological processes embedded in our future production process. Current practice is only furthering environmental damage or, at best, masking deeper issues and surface level changes through the use of eco-gadgets and the like, distracting us from the major issue at hand.
Environmentally sustainable architecture cannot become a passing phase polluted through the over-stylistic interpretations as it has done in the past but instead needs to be incorporated in all future architectural endeavours if human life wants to continue thriving on this planet. The structural approach of environmentally sustainable architecture will need to be carried out in a variety of forms. Assessing the situation of a piece of architecture considering its conditions properly through critical appraisals will lead to the best unique resolution to be created. This relates strongly to the structural efficiency of each form through analysis of the ‘economy of means’.
For this to realistically take shape globally, incremental changes would be extremely important, especially in certain areas of the world where sustainable development has not been readily accepted. This way, all forms of sustainability would be integrated gradually, in line with social change, meanwhile keeping the incorporation of a closed system as the final goal.
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