How the circular economy is redefining construction

The construction industry has notoriously earned a reputation for creating waste – veritable mountains of it, but change is brewing, and it's driven by a powerful concept - the circular economy, writes John Ridgeway.

Instead of the traditional linear model where resources are extracted, processed, used, and discarded, the circular economy envisions a closed loop. Materials are kept in a continuous cycle of reuse, repair, and regeneration, minimising waste and maximising resource value.

In practical terms, this means that buildings are now being planned with disassembly in mind, using standardised, modular components easily salvaged and repurposed. Think Lego blocks for buildings, readily uncoupling materials for future use.

Salvaged bricks, reclaimed wood, and recycled concrete find new life in innovative projects. Imagine weathered barn wood adorning contemporary facades or vintage bricks breathing life into modern lofts. Advanced technologies are also being used to break down complex materials into their base components, enabling their rebirth into entirely new products.

These are changes that cannot come too soon. The construction industry is reported to contribute roughly 30% of the world's total waste. This translates to a staggering 2 billion tonnes of it every year. (Source: NCBI) In the United States alone, over 600 million tons of construction-related waste were generated in 2018. (Source: EPA)

Construction and demolition) waste represents 23% of the national waste stream in the US. (Source: BTS) and between 2005 and 2018, these levels in the US grew more than 10 times faster than in the preceding decades. (Source: EPA)

Demolition debris forms a significant portion, including concrete, bricks, wood, and asphalt. Excess materials from construction processes also contribute, such as unused mortar, drywall scraps, and packaging materials. Contaminated materials like asbestos or lead paint present additional challenges.

Landfills are overflowing with construction waste, occupying valuable space and polluting the environment. This in turn depletes natural resources and contributes to greenhouse gas emissions, but we are at last, waking up to the problem – hence the growing influence of the circular economy.

While the circular economy holds immense promise, it's not without hurdles. Challenges such as market fragmentation, logistical complexities, and lack of standardised practices require collaborative solutions.

However, the opportunities are vast. Shifting to a circular model has the potential to reduce environmental impact by conserving resources, minimising the carbon footprint, and diverting waste from landfills. This in turn offers the opportunity to create new jobs, foster innovation, and unlock the hidden value of waste materials.

This is not just a theoretical ideal - it's already transforming lives and landscapes. In the heart of the Dutch capital, Amsterdam, where the "Circl" building stands as a testament to circularity. Constructed from dismantled office buildings and harbour quays, it houses flexible workspaces, a restaurant, and even a hotel, all woven from a tapestry of repurposed materials.

In Brussels, the ReUseMaterials centre diverts construction waste from landfills, offering salvaged materials at discounted prices. This not only reduces environmental impact but also fuels creative projects and empowers local communities.

Down Under, the "Phoenix II" project showcases the potential of modularity. This multi-story office building boasts prefabricated timber units designed for disassembly and relocation, maximising adaptability and minimising waste.

This is just the start of it. Material scientists are playing a crucial role in transforming the construction industry by unlocking the hidden potential of waste using advanced recycling technologies.

These innovations are breaking down complex materials like concrete, plastics, and even electronic waste into their base components, enabling their rebirth into new building materials - turning discarded plastic bottles into sturdy furniture for example, or shredded tyres into asphalt pavements.

Bioremediation, another exciting field, uses microorganisms to break down and repurpose construction waste like contaminated soil and demolition debris, turning contaminated land and transforming it into fertile grounds for landscaping or urban gardens.

Pioneering bio-based alternatives using plant-based materials, are also becoming more common. Scientists are harnessing the power of renewable resources like bamboo, mycelium (fungal roots), and cellulose to create sustainable building materials with exceptional strength and insulation properties.

Biopolymers, derived from natural sources like bacteria or algae, are also replacing traditional plastics in everything from roofing membranes to insulation panels. Windows made from biopolymers can self-regulate light and temperature, reducing energy consumption.

Material scientists are working closely with architects, engineers, and policymakers to ensure these new technologies and materials are seamlessly integrated into the construction process.

There are many inspiring examples of such breakthroughs. Biohm, a Dutch company uses mycelium to create lightweight, fire-resistant building blocks that can be grown in moulds within days.

Cementos Argos, the Colombian cement giant has developed a technology that captures carbon dioxide emissions from its production process and converts them into new construction materials.

Evocative Design in the US, creates stunning furniture and architectural elements from discarded plastic waste, giving new life to materials that would otherwise end up in landfills.

These are just a few glimpses into the incredible world of material science innovation in the construction sector. As research progresses and collaboration strengthens, we can expect even more exciting breakthroughs that will revolutionise the way we build and interact with our built environment.

So, we can see that the circular economy is a journey, not a destination. Every salvaged brick, every repurposed beam, every innovative design paves the way for a more sustainable future. The worldwide construction industry is joining hands, sharing knowledge, and building a world where we leave no trace, but a legacy of resilience and resourcefulness. It cannot come soon enough.