What would happen if our houses were alive? I don’t mean smart homes where Alexa’s absent voice decides the intensity of the living room light. I mean living houses, which grow, breathe, and even reproduce. The idea may seem somewhat implausible, but, in the face of an environmental crisis, we humans have to think radically about the way we live and build in our environment.
Biology is capable of great feats in engineering, and the next frontier in construction technology may be to make buildings part of nature. My colleagues from the universities of Newcastle and Northumbria and I have created a new research center to study this possibility. Here we have 5 ways in which we think that the buildings of the future can become living and breathing beings.
Buildings that grow
The Hy-Fi facility in New York, which consisted of a 13-meter-high tower, was constructed of mycelium bricks. The biggest obstacle, however, could be to design a structure where the mycelium is kept partially alive and able to grow and adapt. The mice-architecture project, led by NASA’s Lynn Rothschild, investigated this possibility, imagining habitats that can regenerate, even for colonies on other planets.
Buildings that heal
The cracks in the cement of a building are usually the first sign that the end is approaching. You can strain the water and, in the long run, oxidize the metal reinforcements that make the structure stable. But researchers have begun to experiment with cement that can heal itself. One method that seems to promise is that which is being developed by a group led by Henk Jonkers at Delft University of Technology, among others, which incorporates bacterial spores (similar to seeds for bacteria) in the cement mixture.
When water enters through the microscopic cracks, the bacteria are reactivated. The material literally comes back to life and triggers a chemical process that causes new calcite crystals to grow and “heal” the cement. This method is capable of adding decades or more to the life of a building.
From the pieces of limestone shells to the wood of dead trees, we already use natural materials to build. However, this palette of materials could be radically expanded. For example, “Scientific American” magazine has just presented the mycelium, the fungus root system, as a material of the future. Mycelia can grow with just bits of wood and grinds coffee in a very short time, creating materials with very significant structural performance.
Buildings that breathe
Many buildings, especially the glass skyscrapers that serve as offices that can be seen in the great cities of the world, need constant revision and support. Air conditioning systems similar to huge mechanical lungs circulate the air to heat and cool rooms. Of course, you can always open a window to ventilate naturally. But what if the walls themselves could breathe?
Hiroshi Ishii’s group at MIT has developed a material that can alter its shape when in contact with water. These materials consist of layers of bacterial spores (similar to those used to self-heal cement) and latex. When the material dries, it contracts and changes shape.
My group has been taking the first steps to investigate how to expand this method to create entire building membranes that can “sweat” as the humidity inside the building rises. Using latex membranes covered with bacterial spores, the material tenses and opens pores, such as sweat glands, allowing air to flow through the walls when, for example, there is a lot of steam from a shower or a kettle.
Buildings with immune systems
We are surrounded by trillions of microorganisms on all surfaces of our homes, bodies and in the air around us. While we spend millions of pounds a year on antimicrobial cleaners that kill much of this complex ecosystem, it is known that those who live near farms may suffer less from allergic reactions than those who live in urban environments. It seems that being exposed to “good” bacteria helps strengthen children’s immune systems.
In an interesting pilot project, researchers at University College London have begun to investigate how surfaces in, for example, kitchens, can be made bio-receptive, actually promoting resistance to disease-causing bugs. Soon, we may be able to eat our probiotic yogurts in probiotic kitchens.
The fuel cells are integrated into the bricks that could be part of the structural factory of the building besides being its stomach. The bricks will collect leftover water and the bacteria will convert chemical energy, while the waste is broken down into electrical energy. In this scenario, your toilet could charge your mobile phone.
As exciting as it sounds, living buildings have a negative part: they will inevitably die. But buildings already have a life cycle. Apart from the occasional geriatric tourist attractions, most of the buildings are in a state of constant change. When they reach the end of their useful life, demolishing buildings is expensive and also pollutes. Imagine a city of buildings that die delicately and return to the earth, creating the food that the following buildings will use to grow and adapt. Surely it is more exciting than a smart home with a fridge that automatically asks for broccoli when it runs out.