We tend to see eggshells as fragile, but they’re stronger than we think.
Nature Squared, an ethical design studio founded in 2001, has developed a beautiful wall tile made from discarded eggshells collected from bakeries and kitchens on the island of Cebu in the Philippines. It’s the latest project for the Swiss studio, which focuses on transforming natural-waste materials—including abalone shells and feathers—into surfaces used in yachts, homes, and hotels. The company’s broader goal is to divert more waste from landfills and, in doing so, make the highly polluting construction industry more sustainable.
These eggshell tiles, which are called CArrelé (a portmanteau of the French word for square and the periodic symbol for calcium), are the first project from Nature Squared’s new chief innovator, Elaine Yan Ling Ng, who joined the company in 2020. Eggshells are frequently used in medicine to strengthen bones and in dentistry to strengthen teeth, but they also have applications for home design. In addition to being strong and stable, they’re naturally resistant to UV rays. And as anyone who has painted Easter eggs knows, shells are good at absorbing dyes. “They absorb natural colors sustainably in fascinating ways,” Ng says. “We use natural dyes, such as indigo, madder, and chlorophyllin.”
Nature Squared has a factory in Cebu and the craftspeople there collected thousands of organic white eggshells from nearby industrial kitchens. They crush these eggshells into different sizes, from sand to 3-mm fragments. Then they’re combined with a binding agent before being cured at room temperature. They then add natural dyes before baking the composite, and cutting them into tiles.
Lay Koon Tan, who cofounded Nature Squared in 2001 with Paul Hoeve, says this project is particularly ambitious because it aims to divert as many eggshells as possible from landfills, since the decomposition of waste contributes to climate change. In the past, Nature Squared has used eggshells as inlays in tiles, but that required significantly fewer of them. “Inlays are a very laborious process that uses 2,000 eggshells and takes 20 man days for one square meter,” she says. “Crushing the eggshells and molding it into tiles uses 20,000 eggshells and two days to produce the same square meter.”
The resulting tiles, which come in shades of red and brown, have a speckled texture. They’re functional, easy-to-clean, and water-resistant, which make them useful in bathrooms and kitchens. In the future, Nature Squared hopes to use them in flooring.
From the start, Nature Squared has focused on partnering with luxury clients to create tiles and panels for walls and furniture. This was partly to show that waste materials could be used for high-end surfaces, but it was also because these new sustainable materials were more expensive to manufacture. By creating these materials at a greater scale, Tan hopes the company will be able to make them at more affordable prices. “Our hope is that we can make these materials available to the mass market at some point,” she says.
According to Tan, a lot has changed since she launched her business two decades ago. Back then, few people in the worlds of architecture and construction were focused on sustainability. But that has since changed. Now, there’s a growing awareness in the industry that building materials and construction are a massive source of global carbon dioxide emissions. “We know we’re in a race against time,” Tan says. “This is our small contribution toward buying us more time.”
The eggshell tiles are available for purchase through Nature Squared.