Publié le 15 juillet 2019

Nature, a source of inspiration

The architect Mick Pearce sought to optimize the efficiency of energy at buildings and succeeded. His source of inspiration? Termites.

Today, it seems that architecture has no limits: smart buildings, clean energy, structure and thermal materials … When it comes to energy optimization, there are always new developments to incorporate. Those innovations for architects like Mick Pearce, can be extracted from nature itself, as in the case of the thermoregulation technique used by African and Australian termites.

Pearce considered the possibility of incorporating patterns present in nature into his buildings after watching a documentary about termites. It turns out that those amazing insects build their solid mounds, which can reach up to eight meters in height, strategically orienting them to the north. They incorporate central “chimneys” that connect the top of the structure with its base, where most of the colony is housed, and which allows air filtrations to travel throughout the mound. Another outstanding characteristic of termites is the elaboration of mounds itself. Mounds are made of tiny balls composed of sand, saliva and earth. This creates pores of different size through which hot air escapes and cold air enters without affecting its solidity. Consequently, mounds have proved to overcome strong winds and intense rains without inconvenience.

One of his most emblematic works is Eastgate, in Harare, inspired by the mounds of termites. For him, Eastgate buildings are the convergence of two types of architectures: the new order, of brick and stone; and the old order, of metal and glass. Brick and stone serve both to isolate the structure of small windows from the sun and to minimize the overheating of the structure during the day. This “ecosystem”, as he calls it, was inspired by the technique of termites.

Because of its efficiency, the above-mentioned technique has been studied by several researchers. A team led by L. Mahadevan of Harvard University has measured the speed and direction of the wind in the mounds. They focused on the temperature and the CO2 concentration. The conclusion of the study? Mounds behave as if they were lungs which breath once a day.

Nowadays, in terms of thermoregulation, buildings depend almost exclusively on mechanical ventilation: fans, heating and air conditioning. This is because buildings are designed from scratch based on these means of ventilation. Yes, that makes temperature easier to control, but they have a disadvantage that increasingly concerns modern society: high energy consumption. 

The architect from Harare, Zimbabwe, states that the existing relationship between human beings and nature is changing and that this is reflected on architecture. The burning of fossil fuels, which he calls “burning diamonds”, is causing a severe impact from a natural, social and economic point of view. For that reason, in order to meet the needs of modern users, it is necessary to change the focus and use sustainable techniques.

Pearce works with three parameters: nature, resources and aesthetics. As regards the first parameter, he refers to the Gaia theory of natural systems in which life itself controls the biosphere. He argues that designers should see the city as an ecosystem in which all parts are interrelated and influence one another. At the same time, he considers essential to pay attention to human, natural and economic resources. Finally, for aesthetics, he refers to the new relationship that is established between the designer and nature, in which professionals copies the processes of nature but not nature itself.

Eastgate buildings have ten floors and a glass roof, metal bridges and elevators suspended by steel cables. They stay cool in summer and warm in winter without any energy expenditure, thanks to its structure which allows the circulation of natural air currents. Eastgate consumes less than 50% energy if we compare them to buildings with air conditioning: “It was an attempt to design a building based on a living system,” explains Pearce.