A new architectural science that mimics nature: hope or hype?7 min read . Updated: 29 Jan 2010, 12:48 PM IST
A new architectural science that mimics nature: hope or hype?
A new architectural science that mimics nature: hope or hype?
New Delhi: Building a canopy without trees, a ventilation system of a termite hill without termites, or a natural water filtration system without the detritus or leaf litter of a forest floor is not an easy task. Especially when you’re trying to do it with construction material such as concrete, tiles and tar.
In fact, it may not even be the most sensible endeavour, but it’s what HOK, an American design firm, and the Biomimicry Guild, a “consultancy for bio-inspired design", have set out to do at Lavasa, billed as “Free India’s Largest Hill City". The luxury township being constructed on a series of hillocks in the lush Western Ghats, 50km from Pune, by Hindustan Construction Co. Ltd (HCC), has become the country’s architectural testing ground for the fashionable new “science" of biomimicry.
It’s been tried in a few parts of the world, but on a much smaller scale. The Swiss Re building in London, designed by Lord Norman Foster, is modelled on the structure of a sea sponge, with gaps in each floor creating shafts that ventilate the building. The Eastgate Center in Zimbabwe uses ventilation structures similar to those found in termite mounds.
In India, however, the goal is much bigger; a “bio-inspired city" has never been attempted earlier.
To watch a slideshow of human designs and techology that has been inspired by nature, clickhere
The guiding principles of the new science are fairly straightforward. Nature knows best; the “greenest" constructions are those that emulate natural design. The Biomimicry Guild believes that the way to making the city sustainable is to emulate the processes and design strategies of the moist deciduous forests of the region, which they say are “locally attuned, benign, interdependent and optimized".
Shuttling between Lavasa and offices in Mumbai and St Louis, the architects at HOK have been working frantically to translate those principles into practise. Biologists from the Biomimicry Guild have been flown in from across the world; and extensive three-way discussions held between the unlikely combination of biologists, architects and HCC site engineers.
The team started by looking at the dispersal of rainwater through the forest. The area gets over 500cm of rain during the monsoon. According to Dayna Baumeister of the Biomimicry Guild, they found that a surprisingly large component, nearly 20-30%, was returned directly to the atmosphere by the forest canopy through evaporation; 7-10% was channelled to aquifers; 40-60% was absorbed by the soil and the vegetation; and the rest ended up as surface run off.
The “evaporated" component was responsible for keeping the surroundings cool. The multi-layered forest canopy aided the evaporation by channelling air into an updraft. If buildings were to replace the trees, they’d have to be “clustered in a manner resembling the canopy, both vertically and in their spread", says Dhaval Barbhaya, an urban designer at HOK.
That wasn’t the only role the canopy played. It also, along with the undergrowth and detritus, broke the impact of torrential monsoon showers, reducing soil erosion. To have a similar effect, the buildings would need to have sloping roofs, with tiles designed to allow for sufficient run off. But the large tiled roofs would be difficult to keep clean; unless the tile surfaces were such that rainwater washed evenly across them as it cascaded down.
Closer to the ground, the detritus of the forest floor reduced surface run off and directed rainwater to a vast web of tree roots underneath. If Lavasa was to put as much water into the soil as a natural ecosystem did, conventional water harvesting techniques and water storage systems would not be adequate.
To reduce surface run off, the architects would have to use permeable tiles; and explore the possibility of storing water in a network of channels that ran between the buildings.
In the absence of tree roots, says Baumeister, the absorption capacity of the soil would have to be augmented by geomats, mesh like mats that would need to be embedded in the soil. These mats would be made from locally-sourced materials, and would contain seeds of endemic plant species.
All of this together would replicate just one aspect of the forests’ ecology. Similar interconnected measures would be applied to energy use, carbon emissions, etc. Solutions would have to be created using a combination of invention and “conventional" green technologies.
The complexities were daunting, but it was “imperative", explains Barbhaya, “that we understood the system as a whole". Implementing single measures at random would be of limited benefit; and they’d risk missing the proverbial woods for the trees. The plans were ambitious, but progress on the ground has been slow. The partnership between HOK and the Biomimicry Guild is recent, having started in June 2008. Most of their efforts so far have been focused on creating site-specific guidelines.
“At Dasve (the first of the four ‘towns’ in Lavasa), we didn’t really get a chance to implement these measures," says Barbhaya. The only evidence of biomimicry there is in the use of specially-designed roof tiles, and the restrictions on erecting boundary walls, which inhibit the natural dispersal of seeds.
Barbhaya and Baumeister, however, claim that things are falling into place. Field trips to the other proposed sites in Lavasa are complete; and they’re close to completing a metric of 15 elements that will help quantify the ecological impact of a built environment.
These “ecological performance standards", as they call them, create a localized framework to evaluate the carbon fixation, water purification, biodiversity maintenance, erosion control, etc., of any construction. “The metric is being used for Mugaon, the second town in Lavasa, the plans for which will be ready in three months," says Barbhaya. “You’ll see a lot of the biomimetic adaptations there."
The new science has elicited sceptical responses from Indian architects and planners. Rohan Parikh, who heads the Green Initiatives at Infosys, finds it impressive, but is “yet to be convinced". “If someone can prove," he says, “that it is more effective than conventional energy saving measures, I would be happy to use biomimicry in the over 2 million sq. feet of space that I add every year."
Others such as Gaurav Shorey of The Energy and Resources Institute in Delhi are less charitable. He dismisses it as more marketing strategy than substance. “We really don’t need to fly in architects and biologists from abroad to teach us how to construct," he protests. “Indian buildings have traditionally taken local environments and materials into consideration."
But does traditional architecture incorporate features directly inspired by nature? None that he is aware of, but “they’re as ecologically friendly as any modern construction", Shorey says.
Biomimetric buildings, he points out, are not necessarily green buildings. “You can make a building that resembles a beehive or a seashell, or you can try to recreate a forest canopy, but if in the process, you’re using a lot of concrete and metal, then you’re not creating a green building." Biomimicry is only effective if it’s used judiciously.
The principles of biomimicry are also being questioned. Rajan Rawal of the Centre for Environmental Planning and Technology University in Ahmedabad, believes that natural systems and design only make sense in natural settings. “Human beings are not ants," he says. “Materials and designs suited to ants aren’t necessarily the best for humans."
Processes such as photosynthesis, he maintains, are actually very inefficient. They work in the “highly integrated" natural world where plants degrade to provide nutrients to other life forms. The concrete of a building that mimics photosynthesis, however, is rather unlikely to degrade similarly. The current biomimetric approach, Rawal believes, also puts the cart before the horse. “Humans are adaptable creatures," he says, “who can live with a temperature of 20 degrees in summer and 30 degrees in winter." To imitate nature, an inherently flexible and adaptive system, without jettisoning the desire to meet “unnatural" needs such as the constant 24 degrees that air conditioners provide, is contradictory and untenable.
So why, despite the doubts, did HCC chose biomimicry? “Innovation has always been a driver for us," says Krunal Negandhi, assistant vice-president (projects) at Lavasa Corp. Ltd. “We’ve chosen biomimicry on the advice of HOK." The effort, according to him, is “aspirational". They will only be able to evaluate its impact once the measures are implemented on a larger scale, he says.
The proponents of biomimicry at HOK and the Biomimicry Guild are, however, very sure of their approach. In fact, they’ve already embarked on their next project, the massive 7,192ha Khed special economic zone, which is being built by Bharat Forge Ltd and the Maharashtra Industrial Development Corporation.
“There", says Baumeister optimistically, “we plan to approach the industry side of the project from an eco-industrial perspective; creating a food web of industries where waste material from one is raw material for another."
Biomimicry and its concomitant terminology are clearly in vogue. For the time being, it looks like it’s possible to have a food web without food.