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An EPFL scientist has developed an automatic construction method that draws on an unlikely combination of mycology, genomics and architecture. Her method also has the added benefit of being carbon-negative.
Frieda Steinpilz, a scientist studying sustainable construction methods at EPFL, has no qualms about admitting that when it comes to style, her buildings "have more in common with Gaudí or Hundertwasser than with Libeskind." But that doesn't shake her belief that her method has a bright future.
The evidence suggests that Steinpilz's confidence isn't misplaced. Her self-growing building method involves just two ingredients: a splash of water and a pinch of powder - although not just any old powder, of course. "I was amazed to learn about the mycelium-based material being developed by EPFL students that could be molded into different shapes," says Steinpilz. An expert in synthetic biology and genetic engineering, she already holds two PhDs and is exploring this new method as she works toward her third. This broad knowledge base is what prompted her to push the boundaries of cross-disciplinary research - a value that EPFL holds dear.
Genome editing
Instead of mechanically forcing mycelium to grow into the desired shape, Steinpilz's method involves reprogramming the genetic code inside its stem cells. "I had to learn how to decode the fungus' DNA so I could understand which alleles performed which function," she explains.
Her early experiments produced large, misshapen truffles. But with time, as she snipped away at the genome using the CRISPR-Cas9 "genetic scissors," she was able to achieve more precise forms. "Currently, I can code the fungi to grow into 30cm-thick blocks with more or less straight lines," she says. "I added Hox genes - also known as 'architect genes' since they control the final stages of organ development - to halt the growth of the house's walls at exactly the right moment and make the floor-slab section grow horizontally. And I included coral DNA in order to form a reinforcing calcium structure inside the fungi." This calcium framework has another benefit: as it grows, it absorbs a large quantity of CO2 from the air, meaning that Steinpilz's houses act as carbon sinks.
Growing a large detached house in less than two months
Her prototype, which she grew at EPFL before transferring it to a local campsite, is a modest 32m2 property with a bedroom and combined living/dining area. She now spends most of her free time there and says she appreciates the quality of life it offers. Steinpilz is confident that, with more time to fine-tune her method and code new cell-division instructions, she'll be able to grow more complex, multistory buildings. Given the right soil conditions, she estimates it should take just three to four weeks to grow a large detached house, plus two extra weeks for the structure to dry out and stabilize once watering stops. "Obviously, the doors and windows won't grow themselves," she adds with a smile. But her method will save a huge amount of time and resources at the structural-work stage.
More hurdles to overcome
Steinpilz still has to iron out two kinks, although they're not necessarily deal-breakers. First, although drying out the structure stops the fungus from growing, heavy rain could restart the process, potentially causing the house to grow a new story. "That could lead to some administrative headaches, since the number of stories is generally capped by building regulations," she explains.
Second, the fungus retains a relatively potent odor, even when dry. "It's somewhere between truffle and morel," she says. "Personally, I like the smell. But I realize that some people might get tired of it after a while. The good news is that the fungus is edible, so you could take a slice out of a wall and grate it over your favorite dish. It goes particularly well with salmon tagliatelle."
