On a day dedicated to the built environment at COP26, leaders highlight the importance of partnerships in reducing emissions in the sector.

• Buildings and the construction sector account for approximately 40% of global greenhouse gas emissions.

• Chile, the Netherlands and Holcim come together to show how circular innovations and multistakeholder collaboration can help reduce emissions.

A just transition to a circular economy is crucial to achieving climate goals. After all, only 55% of emissions can be tackled with renewables and energy efficiency. The remaining 45% must be addressed by changing the way we produce and consume.

The circular economy’s approach to designing, producing and consuming goods eliminates waste and regenerates nature. In short, it ensures we can live within our means and in harmony with the planet.

The building and construction sector offers huge potential for transformational change. The sector’s greenhouse gas (GHG) emissions account for approximately 40% of global GHG emissions – about one-third from the construction phase, and the remaining two-thirds from buildings in use. Furthermore, approximately 50% of the urban environment needed by 2050 is not yet built. Different building techniques, including more circular cement, steel and aluminum, can help ensure we reach net-zero by 2050.

A number of recent innovations from across the globe show what’s possible when businesses, governments and civil society collaborate to move the construction needle from linear to circular.

Netherlands: circular bridges, an infrastructure marketplace

The innovation: In 2019, a circular viaduct was developed in collaboration between the Netherlands Government and the private sector. Elements of this viaduct were modular and could be disassembled, moved and reused, extending product lifecycles. The viaduct was one of many efforts designed to help halve the country’s use of natural resources by 2030 and achieve a fully circular economy by 2050.

To further maximise the reuse of materials, the Netherlands Department for Public Works together with Rotterdam and Amsterdam, developed a national bruggenbank, or National Bridge Bank. The Bridge Bank is a registry of all (soon-to-be) dismounted bridges and elements thereof. This marketplace for bridges contains information on a bridge’s construction materials and parts available for reuse, and can connect construction companies and municipalities. So far, 13 bridges are registered on the Bridge Bank.

The impact: Modular projects and infrastructure marketplaces are scalable, and are crucial for the development of more circular models in the Netherlands and beyond. These projects demonstrate the vast potential of construction to slash emissions. For instance, in the Netherlands, circular bridges and viaducts can reduce Co2 emissions by up to 63%, and virgin steel consumption by up to 60% simply through the reuse of steel elements.

Switzerland: circular cement

The innovation: Earlier this year, Holcim launched its global range of green cement. The cement delivers at least a 30% lower carbon footprint compared to ordinary cement. In Switzerland, this includes a version called Susteno that contains 20% recycled construction and demolition waste, ensuring 20% fewer resources drawn from nature. It also delivers a 38% lower carbon footprint.

The impact: The company began offering Susteno once authorities adapted the regulatory requirements to allow it, based on scientific evidence of the material’s performance. This circular cement has been applied in landmark structures such as the soon-to-open HSG Learning Center at the University of St. Gallen, a 7,000 m2 work and study facility designed by Sou Fujimoto Architects. Scaling such solutions across global markets could dramatically accelerate the transition to net-zero building.

Chile: recycled asphalt

The innovation: In 2020, the Tobalaba Airport near Santiago de Chile built a new runway using recycled asphalt from an old runway, ensuring that materials did not end up in landfill.

The impact: This led to a 70% decrease in the virgin gravel used, a 74% decrease in waste generation, and a 45% decrease in overall costs. The Ministry of Public Works is already working on expanding these practices to all new airports.

Such projects could have a major impact in Chile. In 2019 and 2020 on average, the public sector in Chile accounted for 55% of all the urban construction in the country. Approximately 18.7% of GHG emissions in Chile are related to manufacturing industries and construction.

Changing economies – changing collaboration

These examples show the power of collaboration to drive innovation and systemic change in infrastructure. Scaling future innovation, however, will require looking closely at how construction projects are planned and funded. Public procurement can be an instrument for positive change. Governments, as the largest consumers, can demand more from vendors, and must create incentives for circular and carbon-neutral projects. While countries may be in different stages of developing and implementing green public procurement policies, it is crucial to ensure that socioeconomic and environmental costs drive the circular transition.

Mindset shifts are also critical. Leaders – in business, civil society and government - need to consider material efficiency as addressing the triple planetary crisis, climate, nature and pollution, simultaneously.

Two initiatives are doing just this:

• CE for Net Zero: as part of the Mission Possible Partnership – CE for Net Zero is building working groups including partners on both the supply- and demand-side, zooming in on different parts of the supply chain to ensure that supply chains incorporate material circularity as a key lever to address greenhouse gas (GHG) emission reduction, and addressing material flows of steel and cement.

• Scale360°: this initiative from the World Economic Forum partners with leading industry groups, governments, young change makers, entrepreneurs, and NGOs to unlock the systemic change needed for circular economy innovations to thrive and scale. Its toolkits and tested methodology help leaders in tech, policy and more explore new technologies and business models to transform construction, among other key economic sectors.

Tackling the challenges in the construction industry, both in terms of building materials used in new construction and improving energy efficiency of buildings in use, will be crucial to reach the goals of the Paris Agreement. By changing the way our supply chains work and stimulating innovative public procurement, we can accelerate innovation, extend product lifecycles and significantly change the way we build for a circular and climate-neutral future.

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Written by

Carolina Schmidt, Minister of the Environment, Government of Chile

Steven van Weyenburg, Minister for the Environment, Government of The Netherlands

Jan Jenisch, Chief Executive Officer, Holcim

The views expressed in this article are those of the author alone and not the World Economic Forum.