Seagrass is a market-ready renewable thermal insulation material that’s easy to process. Photos: dpa
As the world continues to wrestle with climate change, the construction industry is reconsidering the materials it uses. Old hits such as clay, wood and straw are coming back into fashion, and new research is identifying novel approaches with a smaller carbon footprint.
Here are four sustainable building materials you’re likely to see more of in the future.
Seaweed is a market-ready renewable thermal insulation material that’s easy to process. “You don’t have to cultivate it, because it grows on the seabed, ” says Rene Goernhardt of Germany’s Agency for Renewable Resources (FNR).
Because seaweed has a high salt content, it doesn’t burn easily, Goernhardt says. Its effectiveness is comparable to conventional insulation.
And the fibre can absorb a relatively large amount of moisture without losing its insulating effect or mass volume, while many of conventional insulation materials recess when absorbing moisture, resulting in hollow areas that can be susceptible to mould.
2. Reeds and rushes
Reeds are increasingly being discovered as a material for use inside walls
Reeds and rushes might not seem very stable at first glance. But when the hollow tubes are processed as sheets, they can withstand great loads.
“They can be installed in load-bearing interior walls or used as mats for insulation, ” Goernhardt says. He hopes the plants can be increasingly cultivated in large quantities with the rewetting of moors.
Reeds and rushes have been used in construction for millennia.
“The big problem is that many companies are reluctant to give innovative developments in the construction sector a chance, ” Goernhardt says.
Popcorn is increasingly being used in particle board and BalanceBoard – which has been on the market since 2011 – and is about two-thirds wood shavings and one-third popcorn granulate, making it much lighter than conventional particle board.
Alireza Kharazipour’s research team at the University of Goettingen in Germany is even working on making products from 100% popcorn granulate, which can be glued and pressed into shapes such as chairs, slabs or packaging boxes.
The top layer of this sandwich element consists of a thin layer of textile concrete combined with flax.
They picture it as a natural Styrofoam substitute. “It also works as an insulating material or for partition walls in offices, ” he says.
Discussions are underway between the university and several companies about licensing, Kharazipour says. “These products have a lot of potential.” He hopes that they will be commercially available this year or next.
4. Flax-reinforced concrete
The resulting material is durable, corrosion-free and has the same static properties as reinforced concrete, they say, while being cheaper to produce and having fewer CO2 emissions. In addition, flax is versatile – the textile reinforcement adapts to almost all shapes.
Flax-reinforced concrete is not yet ready for building, however. “Unfortunately, the material is not yet fully developed, ” Goernhardt says. – dpa