Could moss-infused concrete be the simple, green solution to many of the climate change issues that modern construction is working to address?
For over a decade, researchers from universities in Spain, London, Pakistan, and the Netherlands have been exploring bio-receptive concrete—commonly known as moss concrete—as a way to enhance urban spaces. This innovative material can green building exteriors, deter graffiti, reduce heat absorption, capture carbon dioxide, and even manage water. Moss roots (or rhizoids) adhere to the concrete without penetrating it, and some studies suggest this root network might even increase the concrete’s durability.
While the concept has gained traction across Europe, it remains largely unfamiliar in North America.
“Moss, when applied properly, can be both durable and aesthetically pleasing, serving as a biophilic installation,” said Bill Browning, managing partner of Terrapin Bright Green, an environmental strategies consulting firm based in Washington, D.C.
However, Browning is not aware of any moss concrete projects in North America. His firm experimented with growing moss on crushed glass on walls, but the project did not succeed.
Bio-receptive concrete refers to a type of concrete specially formulated to promote moss growth, or designed with a textured surface that encourages the plant to grow.
“The construction of moss concrete involves a traditional concrete base for structural support, a waterproof layer for protection, and a top layer designed to allow rainwater to seep through and support moss growth,” explained researchers Muhammad Awais and Safeer Ullah Khattak from Islamabad’s Capital University of Science and Technology.
Their 2023 study, “Exploring the potential of moss concrete as an eco-friendly solution to mitigate urban heat island effect,” presented at the fifth Conference on Sustainability in Civil Engineering, found that moss can help reduce urban heat, improve the durability of building materials, regulate surface temperatures, and absorb up to 20 times its weight in water.
Stephen Peck, president of Green Roofs for Healthier Cities in Toronto, noted that moss concrete is still in its early stages in North America and that there are no known installations yet.
“It’s an emerging technology we’re monitoring,” he said. “There’s a lot we don’t know.” Peck also emphasized that moss alone isn’t a complete solution for water management on sites.
Instead, Peck pointed to the development of a broader municipal approach, such as “sponge cities,” which integrate water management techniques across buildings, streets, and other urban areas to handle flood runoff.
As moss concrete technology continues to evolve, so do the methods for mixing and preparing the material. Researchers Max Veeger, Marc Ottele, and Alejandro Prieto at the Netherlands’ University of Technology have worked on creating affordable bio-receptive concrete substrates. Their research, published in the Journal of Building Engineering (December 2021), tested four approaches: changing the aggregate to crusted expanded clay (CEC), adding bone ash, increasing the water-to-cement ratio, and using a surface retarder. They found that the use of CEC, bone ash, and surface retarders significantly increased the material’s ability to support moss growth.
Additionally, their study debunked the earlier assumption that a pH below 10 was necessary for biological growth, revealing that moss can thrive in higher pH conditions.
Marcos Cruz, a professor at the Bartlett School of Architecture in London, has been examining how bio-integrated architecture can integrate hydrophilic conditions—those conducive to plant growth—into building designs. This approach targets poikilohydric plants, like algae, mosses, and lichens, using innovative designs such as textured panels that capture water and offer protection from wind.
The company Respyre, based in the Netherlands, has brought moss concrete research to the commercial market. It uses recycled concrete in its manufacturing and has completed projects on residential buildings, industrial structures, and even on wind turbine bases, sound barriers, and bridge underpasses, areas prone to graffiti. Drawing from research at Delft University of Technology, Respyre developed its own moss-growing gel and is now working on large-scale commercial projects. However, they have not yet provided further details.