How Nature's Blueprints Inspire The Next Generation Of Sustainable Architecture

A computer model of the Liuzhou Forest City, a green city concept designed by Stefano Boeri Architetti.

Imagine a city: the endless thrum of cars, the cacophonous chatter of the busy, and the blinding light of digital signs. Our cities have opened doors of freedom to independence, employment, and urban living for generations. Yet, they've intensified environmental challenges such as wasteful energy consumption, poor water management, and air pollution. As humans, cars, and buildings continue to congest cities, there is still a need to break beyond traditional cities' confines to create sustainable buildings and design long-standing structures. And thus, where else can we go for inspiration than the one and only nature, which has lived, survived, and endured the Earth much better than we ever could? Sustainable architects at the forefront of architectural change use their imagination without bounds: think of termite mounds, lotus leaves, honeycombs, and seashells. However, it is not entirely evident from this list how such natural forms will be transferred over to building designs. Sustainable architects do not replicate nature; rather, they mimic it.

This is known as biomimicry, the innovative learning process of taking cues from nature's proven models and designs to solve our cities' current issues. For example, while a building's temperature can be controlled by air conditioning and heating, which are expensive, energy-thirsty, and difficult to service, inventors observe how termite mounds maintain a stable temperature through clever ventilation. Termites, using soil, saliva, and vegetable scraps, build mounds with thick walls that gain heat during the day and release the stored heat slowly at night, keeping the termites safe from extreme temperature fluctuations. The second natural engineering aspect of termite mounds is the tiny networks of tunnels and vents within, employing convection currents to maintain the interior at a constant temperature. Because the exterior of the mound is heated throughout the day, the air inside the tunnels heats up, becomes less dense, and rises naturally. The cold air, which is more dense, sinks to the bottom, pushing the warmer and less dense air to leave through the vents. The denser and colder air, on the other hand, descends and cools the interior of the termite mound.

Architects who take inspiration from nature’s principles try to implement a similar passive ventilation system in buildings to make them more energy efficient. This is mainly done through careful planning of where vents are placed. Some buildings harness natural convection, where cool air is drawn in from lower openings while warm air exits through higher vents. This method mirrors the termite mounds and significantly reduces the need for air conditioning and heaters. Most buildings are made from concrete, not only because it’s low maintenance but also because concrete, like the termite mound walls, has a high thermal mass. In fact, most concrete buildings use 20% less energy for heating and cooling.

What about lotus leaves? While these leaves are not particularly known for being robust or well-designed, lotus leaves are actually, like termite mounds, extraordinary under the microscope. The surface is not smooth, and it contains a unique design of bumps and ridges visible only at microscopic and nanoscopic scales. This helps the leaf capture air particles in a way that makes it so that there is less direct contact between a water droplet and the leaf’s surface. This leads to a phenomenon known as superhydrophobicity, or the repellence of water, whereby the water organizes itself into perfect spheres and rolls off the leaf. The lotus leaf's waxy coating also prevents contaminants from being absorbed by the leaf. So, when the water is repelled and rolls off the leaf, it also carries whatever is sticking to the surface. Through biomimicry, newer buildings are able to use this concept to passively clean their exteriors. This is especially helpful for extremely tall buildings, where it is hazardous and time-consuming to clean the outside surfaces manually.

Applying waxy coatings, like those found on lotus leaves, to bumps and ridges on concrete surfaces, window panels, and metal creates a superhydrophobic surface on the building’s exterior. So, whenever it rains, the water not only gets repelled and pushed off, but it also takes whatever is built up on the exterior surface of the building away with it, allowing the building to stay clean for longer and getting rid of the need to manually clean the building’s exterior. Another added benefit is that the water cannot corrode or stain the metal on buildings, as the waxy layer protects it from direct contact with water or other elements. 

Looking to the future, it becomes clear that biomimicry will become more and more prevalent in our buildings, especially as the world changes to exist harmoniously with the natural functions of our planet, not against them. With global climate change, atmospheric pollution, and the increased requirements for buildings as cities take up more land, biomimicry can help create clean, comfortable, and cheaper spaces to live in. The primary limitation of designing buildings inspired by nature is that it’s often challenging to understand how natural systems perform under harsh conditions. Many natural phenomena remain unexplored by scientists, and even when insights are gained, translating them into practical urban building designs is a complex process involving significant trial and error. With biomimicry, we can embrace nature and protect it. Biomimicry is a step towards our green future, and we need to address the fundamental environmental problems in our society to redefine how we interact with the Earth.