The circular economy is the green way in construction

The Earth's temperature has already risen by 0.8°C in the last hundred years. There has been a significant acceleration in the last 30 years, with 75% of the increase occurring during that time. Scientists generally agree that global warming is man-made. There has been a large increase in greenhouse gas emissions, especially carbon, in recent years due to increased industrialization.

I am a structural engineer by training, and I have been working on climate issues since I went to the United States for graduate studies in 2008. I have been examining how (or if) climate change will affect weather patterns and, consequently, the built environment. I have found that climate change can lead to increased precipitation, more days of precipitation, and that extreme weather events can become both more powerful and more frequent. If so? Don't we then need to account for these changes when we design buildings and other structures? Can we simply design buildings based on the assumption that the climate will remain stable, i.e., that it will not change over the building's lifetime? Don't we need to account for this variability in weather and the loads our buildings are subjected to?

These are the questions that have been fundamental to my research since I went abroad for graduate studies. In 2018, I moved home from the United States and started working at the engineering firm VSÓ Consulting. I was hired to develop and manage VSÓ's Green Path, which provides consulting on sustainability in construction. When I discuss climate issues and the construction industry, there are two main sides to this major problem;

1. Do we need to do something differently to cope with the changes in weather and loads that are already underway?
2. Can we build differently or with different materials to ensure that the construction industry is doing its part to reduce carbon emissions?

Until now, the construction industry's role in Iceland's climate accounting has been underestimated and little discussed. The total emissions from the construction industry in Iceland have not yet been estimated, but that work began in early 2021 under the direction of the Housing and Construction Authority. The project is called Building a Greener Future and is a collaborative effort of key stakeholders in the construction industry. VSÓ Consulting is participating in the project, and I am the group leader for the measurement group, whose role is to measure or assess carbon emissions from the construction industry in Iceland. Once we see figures from this work, we can systematically begin to evaluate the benefits of actions and subsequently develop solutions that minimize emissions from buildings and other structures.

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Globally, it is estimated that the construction industry is responsible for about 40% of carbon emissions worldwide. These figures clearly show that the construction industry is a crucial link in ensuring the sustainability of future generations. The circular economy is one of many solutions that reduce the carbon footprint of the construction industry. I would like to take this opportunity to discuss the circular economy a bit and how I believe it will play a key role in promoting solutions for the construction industry, which is by its nature very conservative. As it stands today, the construction industry is largely based on a linear economy, i.e., building products are manufactured, used, and then finally disposed of. It is this linearity of the construction economy that makes the construction industry responsible for about 40% of the world's raw material and resource consumption, 40% of carbon emissions, and over 40% of man-made waste. Society has begun to call for action on climate issues, and therefore, one of the main goals of the City of Reykjavík in the draft Climate Action Plan for 2021-2025 is to implement a "circular mindset." A "circular mindset" is about introducing new thinking in design and material handling so that natural resources are not depleted and waste sent to landfills becomes a thing of the past. It is important that property owners look at the opportunities and actions inherent in the circular economy and can formulate a future policy for sustainable development. The leading experts in these matters estimate that it is possible to reduce carbon emissions from the construction industry by 38% if a circular mindset is applied.

How should we implement a circular mindset in the construction industry?

The most environmentally friendly option is to build nothing new. We therefore need to look at the buildings we already have as material banks where we are “storing” building materials for the next phase of use. Property owners can have Reuse Plans carried out to map their property portfolios. The aim of these plans is to maximise the value of assets and thus promote sustainability by better utilising or selling building components that would previously have been discarded. The Reuse Plan includes a quantity take-off of the main building components. The plan involves an analysis of ways to reuse building components as well as possible recycling channels for materials that cannot be reused. It is also possible to assess the carbon footprint saved by reusing the building components. By reusing building components in future projects, it is possible to significantly reduce the carbon footprint as well as preserve natural resources.

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We also need to rethink how we design buildings and building components. They need to be specifically designed so that buildings or parts of buildings can be disassembled. We need to look at how we can achieve these goals and withstand stress requirements from earthquakes and wind. When building circular buildings, it is also necessary to ensure that the finishing is of high quality so that connections can be accessed without depreciating the value of the building components. Education needs to be initiated, for example, by Iðan, where interested parties can learn how to disassemble a building to preserve its components. A lot of development work needs to take place so that we can design and construct buildings that can be disassembled and reused. In this way, we ensure flexibility in buildings and maximise the utilisation value of building components, thus promoting sustainable development.

I envision a future where we have mapped all buildings in Iceland and defined the reuse potential of buildings, building components, and building materials. I envision us designing houses that can be pieced together in many ways and reused according to the changing needs of society.

Author: Sigríður Ósk Bjarnadóttir, PhD in Structural Engineering, Specialist in Sustainability and Climate Issues in Construction, Project Manager of the Green Path at VSÓ Consulting.