The Circular Economy in Construction

How do we define the circular economy?

A circular economy (sometimes referred to as circularity) is a model of production and consumption, which involves sharing, reusing, repairing, refurbishing and recycling existing materials and products for as long as possible. The principle aim of the circular economy is to help tackle global challenges, such as climate changes, biodiversity loss, waste and pollution.

In a circular economy, manufacturers design products to be reusable. For example, electrical devices are designed in such a way that they are easier to repair. Products and raw materials are also reused as much as possible. For example, by recycling plastic into pellets for making new plastic products.

What do we mean by a linear economy?

A linear economy traditionally follows the take-make-dispose process. Essentially, raw materials are collected, and then transformed into products that are used until they are finally discarded, when no longer required or at the end of its useful life, as waste.

What happens in the reuse economy?

As the illustration below shows, the reuse economy keeps valuable resources in circulation to lower the impact on the environment. The aim is to use a product over and over again, and therefore to extract the maximum benefit from it, before breaking it down to its constituent parts and recycling it. It is the transition stage from linear to circular.

How can the application of the circular economy drive greater sustainability and new business opportunities in construction?

The construction industry is one of the world’s largest consumers of energy and raw materials. Fact. And, this is taking its toll on the environment. In the EU, construction is responsible for circa 40% of CO2 emissions and a third of all waste. Moving from a linear to a circular economy would therefore yield huge ecological improvements. There are also considerable economic advantages, world-wide the opportunity is thought to be several trillion dollars per year.

For the construction industry the transition is about considering how to maximise the lifespan and reusability of an entire building and/or materials at the very start of the design process.

In RIBA’s publication Building Revolution they have set out their circular economy design principles;

• The first design principle is to build in layers. Buildings are made from thousands of components with varying lifespans, hence the idea of building in layers. As each element is independent, this allows for different layers such as the façade or internal finishes to be removed and salvaged without damaging adjacent layers.
• Designing out waste is the second principle. Requiring designers to think about the whole-life of a building, from the decision to build new or refurbish, to its eventual demolition or deconstruction. It is important to prioritise refit and refurbishment and using reclaimed materials and remanufactured products.
• Designing for disassembly is the third principle. Building that can be deconstructed and their components and materials reclaimed during renovation or demolition.
• The final design principle is the selection of materials. Careful selection of building materials and products is the bedrock of circular economy thinking. Replacing materials that are difficult to reclaim or recycle.

World-wide we need to move away from the recent trend for stripping out buildings every few years and tearing them down well short of the end of their design life. New buildings are constructed from components made from hard-won virgin materials with virtually no reuse or reclamation. It is estimated that the global built environment demands around 40 percent of the world’s extracted materials. Plus, demolition waste is the largest waste stream in many countries. This is clearly highly wasteful, and with little thought given for the future.

Applying circular economy principles to buildings uses fewer resources, enables adaptation for different uses and can even provide healthier environments for people to live and work in. They also create an opportunity to design buildings that are not simply consumable goods, leaving a positive legacy for future generations.