Using Bio-Based Materials to Build Cities
Did you know about 56% of the world’s population live in cities? The population numbers of urban dwellers are expected to double by 2050 when nearly 7 out of 10 people will live in cities. Cities are polluted due to industrial and motorized transport systems that rely on fossil fuels. The infrastructure that makes up cities is also constructed with carbon-intensive materials. As a result, cities account for over 70% of global carbon dioxide emissions.
We can’t eliminate these systems that make up our cities, but we can use bio-based materials to make them more sustainable. Carbon emissions could be significantly reduced if just a small percentage of new infrastructure in cities is constructed using sustainable bio-based materials. Moreover, these new buildings could also boost carbon storage and help us reach net zero.
Bio-based materials are catching on in the construction industry. They are materials that grow or are a natural part of the biosphere. Bio-based materials include Timber, straw, hemp, cork, clay, and earth. Besides being honest, these bio-based materials are renewable and have a lower, neutral, or negative embodied energy and carbon than traditional construction materials. Timber, for example, has around three times less embodied carbon than steel and over five times less than concrete.
The construction industry accounts for more than 39% of energy and process-related global carbon emissions. Using timber for building, it can store carbon rather than emit it. The Stockholm Wood City will be built in Sickla, Sweden, and is said to be the world’s biggest wooden city. Wooden construction means a significantly reduced climate impact during the construction phase and the whole life cycle. It also has a faster and quieter construction process.
Another bio-based material emerging in the construction industry is algae. Algae are being used in building facades as a sustainable way to generate heat and biomass for various purposes. The algae act like double glazing, but there is water and algae instead of air between the two panes. The algae will also absorb carbon dioxide and insulate the structure.
Hempcrete is a composite material made from hemp hurds, lime, and water. It is a strong, lightweight, and fire-resistant material that can be used for a variety of building applications, such as walls, floors, and roofs. Hempcrete is considered to be a carbon-negative bio-based material. It absorbs more carbon dioxide from the atmosphere than it produces during its production and use. Further, the production of hempcrete also requires less energy than the production of traditional building materials, such as concrete.
Because hempcrete is a good insulator, it can help to keep buildings cooler in the summer and warmer in the winter. This means that less energy is needed to heat and cool buildings, which reduces the amount of carbon dioxide that is emitted into the atmosphere.
Kenaf is a type of fiber that is made from the stems of the kenaf plant. It is a strong, durable, and lightweight fiber that can be used to make a variety of building materials, such as bricks, panels, and insulation.
Miscanthus is a type of grass that is grown for its biomass. It can be used to make a variety of building materials, such as boards, panels, and insulation.
Other benefits of using bio-based materials in the construction industry are that it helps to stimulate local economies, job creation, biodiversity and reforestation efforts. Using natural materials can help provide affordable and sustainable housing at scale.
While getting the entire construction industry on board with bio-based materials is challenging, some countries are trying to ensure this becomes the norm. The French government has ruled that any public construction financed by the state must contain at least 50% bio-based materials. Amsterdam requires that 20% of the city’s housing projects be constructed with bio-based materials starting in 2025.
As cities and population sizes grow, we will see a rise in carbon emissions. If the construction industry turns to using bio-based materials, there is a chance that we will see healthier cities and a healthier planet over time.
Source – Happy Eco News
August 16, 2023