Buildings that live and breathe

Imagine a building that can breathe through thousands of pores. Sounds outlandish? An engineer from the University of Stuttgart in Germany has recently made it happen. Tobias Becker has designed a façade that adapts indoor temperatures to create a comfortable environment for people in the building. And the energy required is minimal. The system consists of small holes in the surface of the building that open and close to let in just the right amount of air and light.

Tobias Becker drew his inspiration from the skin of living organisms. Skin can regulate its permeability to control the light, heat and other substances that flow between the inside and outside of the body. Becker’s invention is an example of biomimetics or biomimicry applied to architecture. The goal is to imitate biological systems to develop more eco-friendly construction solutions. The European Commission reports that buildings account for 40% of energy consumption in Europe and 36% of its CO2 emissions.

“A few years ago, humans were building ‘machines for living’,” says Leonardo Saavedra, a PhD student at the Technical University of Munich (TUM) who is studying the potential of biomimetic applications based on the skin in construction. “But architects now realise the limitations of this approach and are exploring ways of designing more sustainable, energy-efficient buildings.”

Examples of architectural biomimicry abound worldwide. London’s 30 St Mary Axe skyscraper, better known as the Gherkin, features a ventilation system similar to that of sea sponges. The innovation achieves energy savings of 50% over a traditional tower of equal size.

The surface of the Eastgate centre in Harare, Zimbabwe is covered in openings. Its architect designed it after watching how termites bore holes in their mounds for ventilation. The centre has no air conditioning system and only requires a tenth of the energy used by a similar building.

Esplanade Theatres in Singapore

Surface structure of the Esplanade Theatres in Singapore for better heat regulation inspired by polar bear fur.

New fur coat

The surface of the Esplanade Theatres in Singapore is modelled after polar bear fur, a highly efficient system for regulating heat. The arts complex is covered in 7,000 triangular shades made of aluminium. Photoelectric light sensors adjust the angle and direction of these “shields” depending on the sun’s rays.

This lets light in while preventing overheating. Energy Star, the U.S. government programme set up to promote energy efficiency, estimates that this type of reflective surface cuts the demand for air conditioning by 15%. “So-called ‘smart façades’ have enormous potential, especially during periods of sunshine,” says Jan Hensen, a professor with the Department of the Built Environment at the Eindhoven University of Technology. “A building envelope covered in photovoltaic panels can be used to collect electricity while also acting as a ‘shield’, for example, thus reducing the need for air conditioning.”

The Centre for Sustainable Building at TUM is also looking into these smart façades. One of the centre’s teams is developing a transparent building surface made with liquids and insulating glass. The liquids control the flow of energy between the outdoors and the building’s interior, while the glass improves its thermal performance. Again, the technology results in signi-ficant energy savings.

The BIQ House in Hamburg has gone a step further by directly integrating living organisms into its structure. Its transparent surface contains micro-algae that affect the amount of light entering the building.

When the sun is shining bright, the algae grow by photosynthesis and filter out the sun’s rays. If there is no sunlight, the algae do not multiply, letting sunlight in. Energy savings can reach up to 50%.

“Today, we have the resources to apply certain biological processes to technology,” Leonardo Saavedra says. “Many natural systems adapt to their environment, providing ideal end solutions.” Luc Schuiten, a Belgian architect who designs futuristic urban ecosystems, believes that bio­-mimetics is just a step towards a future more in harmony with the environment. “Humans have been using destructive building techniques since the industrial revolution. Other methods are available.”