Using Waste as Alternative Construction Materials
Using waste organic materials in construction can help cut embodied carbon emissions and divert waste away from landfill and incineration. In the seventh edition of our construction magazine Building Sight, we look at how the construction industry is tackling environmental issues and aiding countries to reduce emissions and meet ambitious targets.
A growing focus on the circular economy (where everything is engineered to be constantly reused or recycled), particularly in Europe, is driving the creation of a new generation of building products, based on waste from crops. Expanding the use of organic waste in construction could reduce reliance on raw materials and allow a new economy to flourish.
A kilogram of waste used as interior cladding, for example, would sell for between €5/kg and €6/kg, according to multinational professional services firm Arup. If incinerated for energy recovery, on the other hand, the
same material’s commercial price would be about €0.85/kg.
Over 100 companies around the world produce building products from agricultural or food waste — ranging from interior partitions and finishes to insulation materials, furniture, and cladding — according to Arup.
Their report showcased 10 companies, 7 of which are based in Europe, producing products from 12 different crops. While some products are certified for use in global markets, others require further R&D and investment.
Hempcrete — a bio-composite material comprised from wooden refuse removed when processing hemp and lime — is already widely used around the world.This is particularly true in France, where it is used to construct non-weight-bearing insulating infill walls, or to renovate old buildings made of stone or lime.
UK startup Chip[s] Board has developed a sustainable alternative to medium-density fibreboard that can be biodegraded into fertilizer at the end of its life. It combines a non-toxic binding agent, made from potato peel, with fibers from waste potato skins, bamboo, beer hops, and recycled wood.
A more high-tech application, from Dutch firm Aectual, uses bioplastics made from renewable plant-based polymers to 3D print floors, façades, stairs, or even entire buildings.
Market acceptance of these new materials will hinge on factors such as reliable technical performance, standards, and regulations, says Joachim Fliege, senior engineering specialist at Marsh in Germany.
“They will need to perform at least as well as traditional materials in terms of durability, fire resistance, safety, and health. And where standards don’t yet exist for such products, independent testing and certification is a must.
“Even though these building materials are somewhat more expensive, a good CO2 balance makes them absolutely competitive compared to conventional materials.”