WHAT IS CIRCULAR CONSTRUCTION?

 

"The construction and demolition of buildings account for around one-third of global material consumption and waste." - Ellen Macarthur Foundation

We are extracting and dumping resources at an unsustainable rate, and with global construction output projected to grow 85% by 2030, there is an urgent need for the construction sector to transition from a linear into a circular economy.

The linear economy in construction follows a "take-make-waste" model wherein we extract raw materials for construction and once used, buildings are demolished and materials are often discarded or downcycled.  

This image is a diagram of the linear economy in construction in a series of three images. The first one is a line of materials, represented by graphics of glass/windows, I-Beam steel, a stack of bricks, and a block of concrete, each with bubbles that form into one cloud with CO2 signifying carbon emissions coming from extracting raw materials. An arrow points right to the next image, which is a teal building with some surrounding trees. The next arrow points right to the third image, which is a yellow skip with a pile of rubble, with a bubble of CO2 coming from the rubble.
Linear economy in construction

A circular economy is an alternative model in which we keep resources in use for as long as possible, extract the maximum value from them whilst in use, then recover and regenerate products and materials at the end of each service life. Circular construction therefore aims to close building material loops by reusing, sharing, leasing, repairing, refurbishing, upcycling or recycling rather than continuing the traditional take-make-consume-dispose process. It is about considering how to maximise the lifespan and reusability of entire buildings or materials at the very start of the design process. 

This image is a diagram of the circular economy in construction. It is a series of 5 images in a rectangle, with arrows pointing right into each other. One image has a pile of materials such as glass, bricks, steel, concrete, and stones. They are transported on a lorry to be constructed, showing a crane putting building blocks on top of each other. The next image is a building, the next is the building refurbished and transformed, the next is the building being deconstructed piece by piece with a crane. It the goes back to the materials image to restart the circular cycle.
Circular economy in construction

By adopting the circular economy, the construction industry can significantly reduce the amount of virgin materials needed and waste generated. The Ellen Macarthur Foundation have forecast that a circular scenario could reduce global CO2 emissions from materials used in the built environment approximately 38% by 2.0Gt in 2050. 

Many techniques, tools and approaches related to circular construction have been developed and tested around Europe. These have served as great showcases for individual circular projects in the built environment, but circular techniques are yet to be demonstrated effectively at a city or regional level with policy and planning impacts considered as part of the vital building blocks for facilitating systemic change.  

Cities hold the key to this transition to a resource and material efficient and regenerative society. As public authorities they must seek collaboration with industry in order to find new ways of confronting the growing scarcity of materials and building a new urban agenda on circular economy.