What is Circular Economy and why is it so important?
Circular Economy has become one of the most discussed topics within the construction industry in the past years. The reason is that the construction industry has high material needs and creates large waste quantities. Specialists have identified enormous potential within waste management, material flows and efficiency, which if realised, will impact the environment and the economy considerably.
Linear and Reuse Economies
To understand circularity one needs first to understand what Linear Economy is. Linear Economy is the economy we have today. It has been named linear because it involves, as figure 1 indicates, a one-way flow of materials. Not many items in today’s market get designed or produced with a mindset to be used more than once. We can alternatively call it Waste Economy, as everything consumers buy has an expiration date and will eventually be disposed.
Some countries have taken the first step in the right direction and have transformed to Reuse Economies by introducing recycling (Fig.2). Recycling creates the first loop with focus on reducing our material needs as part. In this first loop, the used materials that are recyclable and would in a Linear Economy turn into waste, are used again to create new products.
Did you know? Reuse economies collect for example waste glass bottles to create new ones instead of extracting raw materials from nature. However, even though recycling is an excellent way to reduce waste, it is not feasible for all materials. Many elements can not return to their original state and hence are impossible to recycle.
The takeaway: Recycling reduces waste but it does not eliminate it!
Why a circular economy is essential for our future
Scarcity of materials
Unfortunately, none of the materials found on earth are inexhaustible, which gives us the responsibility to find alternatives to fulfil the demand for resources. An excellent example is sand. Did you know that the world is running out of sand? It might sound unthinkable, but sand is actually the world’s second most consumed natural resource after water. The demand for sand is very high in order to manufacture resources such as concrete, asphalt, glass, tv screens and so forth — a key substance in the construction industry.
To put this theory into perspective we can look at the overshoot days of different countries in 2020. An overshoot day shows when a country has used more resources than it can replenish that same year. For example, the USA’s overshoot day in 2020 has an ecological footprint per person that is greater than the global biocapacity per person and they already used their yearly resources on the 14th of March! That means that it would take 4,9 earths if everyone used resources like America. Norway, would need 3,3 earths, whereas Indonesia’s economy pattern is very close to needing just the one planet that we have.
Can material scarcity be avoided?
Since material scarcity is something that can change our or our children lives, we need to change the way we operate. If we would like to somewhat preserve the quality of life that we have achieved, we either have to reduce consumption or transform consumption to a more sustainable mechanism (most likely a mix of both).
Circular Economy, the key to a sustainable future
Circular economy can be differentiated from the previous two economic systems through its annular nature. This implies that the material flow models are turned into efficient flows where waste is close to zero. The way to achieve zero waste is to turn waste into resources or to eliminate waste even before the material has reached the point to become unwanted. This is what we call a closed-loop (Fig.4).
How to achieve zero waste:
- Reducing waste with efficient use of materials, innovation, changes in the production methods etc. (e.g. hollow-core slabs)
- Upgrading rather than wasting (e.g. renovating a building instead of demolishing and building a new one)
- Reusing: using the same material/element to fulfil the same purpose as before (e.g. a door from a building removed and implemented into another building)
- Upcycling: turning unwanted materials/elements into products with a new purpose and higher value (e.g. turning the ventilation ducts into facade elements)
- Repairing broken or old products so that they can return into the market (e.g. fix and paint an old piece of furniture)
- Product as a service: instead of buying a product one buys the service and does not need to care for the waste management (e.g. Philips lighting as a service)
- Prioritizing the use of recycled materials and recycling all materials that are possible to recycle (e.g. recycling drywalls or glass)
- Choosing quality over quantity makes materials/products last longer hence reduces the need of buying more
- Legislation that stimulates circular economy (e.g. by forbidding single-use plastics)
The most common of the methods above as per today are recycling and repairing, but there is so much more that can be done by governments, companies and even individuals. Our everyday choices do affect tomorrow’s waste.
5 things the building industry can do today to reduce waste:
- Renovating buildings instead of demolishing and building new
- Using less concrete and replacing it with certified timber
- Designing flexible buildings that can easily be repurposed or adjusted in the future
- Create modules that can be easily dismantled and reused
- Choose materials without hazardous substances that can be used again
References:
https://unesdoc.unesco.org/ark:/48223/pf0000108730https://www.bbc.com/future/article/20191108-why-the-world-is-running-out-of-sand
