Circular construction and materials for a sustainable building sector

10. 05. 2024

The construction industry still represents one of the largest global energy consumers, but it has great potential for decarbonisation if circular construction principles are to be adopted. The European Union is pushing for the implementation of innovative and sustainable processes to achieve a paradigm shift towards circular construction. This article explores the potential of circularity to revolutionise the way we build, and envision, our built environment.

The construction industry is one of the largest consumers of energy and raw materials globally. Within the EU, it contributes to nearly 40% of emissions and accounts for almost a third of all waste generated. Only around 40% of construction waste undergoes recycling or reuse during building demolition. Typically, recycled construction materials find application in secondary construction rather than in new building projects. Embracing a circular approach within the building sector holds significant promise for delivering environmental, social, and economic advantages. For this, circular construction necessitates a re-evaluation of building design practices, focusing on reducing embedded carbon, utilising recycled or bio-based materials, designing for material and component reusability, and prolonging building lifespans through better maintenance. 

How can circular construction be defined? Circular construction entails the creation, utilisation, and repurposing of buildings, construction elements, products, materials, spaces, and infrastructure, all while minimising the depletion of natural resources, environmental pollution, and negative impacts on ecosystems. Specifically, regarding buildings, a circular structure maximises resource utilisation and minimises waste across its entire lifespan. If a new construction is built, it should be designed for longevity, adaptability, and disassembly. New buildings should be built efficiently and with recycled, renewable, and non-polluting materials. According to the “Circular Buildings and Infrastructure” report by the European Circular Economy Stakeholder Platform (ECESP), the main aspects of circular construction include:

• Design for deconstruction
• Material reuse and recycling
• Resource efficiency (e.g. by choosing efficient design that minimise material waste, adopting prefabrication techniques, implementing lean construction practices, etc.)
• Circular business models
• Digitalisation and data management that can support better tracking and management of materials and support decision-making.

Recognising the construction sector as one of the eight sectors with the highest circularity potential, the EU Circular Economy Action Plan delineates a series of actions to be undertaken. Additionally, the Waste Framework Directive prioritises construction and demolition waste as a priority. Local and regional authorities wield the potential to steer transformation within the construction sector. In fact, given their management of an extensive array of public buildings and considerable purchasing power, they can significantly influence market conditions.

The importance of the net-zero agenda is widely recognised, however there remains considerable discussion regarding its integration with improvements to the built environment. Strategies such as reducing energy consumption, optimising designs, employing low-carbon materials, and embracing digital technologies all contribute to this goal. Nonetheless, it is imperative to adopt circular economy principles, wherein buildings are conceived to be assembled, utilised, disassembled, and repurposed as necessary. This approach not only aligns with the net-zero agenda but also prioritises waste reduction in building design.

The European Union has committed to achieving climate neutrality by 2050, aiming for an economy with net-zero greenhouse gas emissions. Given that Europe's buildings account for 40% of total energy consumption and 36% of CO2 emissions, significant efforts have been directed towards enhancing the energy efficiency of buildings during their operational phase. However, it is essential to also consider CO2 emissions generated throughout other stages of the building's value chain to achieve rapid emissions reductions. Addressing embodied emissions presents a challenge for the EU in decarbonising the built environment, as they are currently categorised within the industrial and waste sectors rather than the building sector. These embodied emissions are estimated to comprise between 10% and 20% of construction-related CO2 emissions in the EU, and in certain European countries, this figure could be as high as 50%. To effectively decarbonise the built environment, circular economy and circular construction offers a pathway to ensure the efficient use of resources and to mitigate embodied emissions generated across various stages of a building's life cycle.

European policy context in circular economy

Circularity in construction is regulated through several directives and frameworks within the EU. Here are the most relevant:

• Circular Economy Action Plan

  It paves the way for a cleaner and more competitive Europe, and it is one of the main blocks of the EU Green Deal. The plan supports the EU´s transition towards a circular economy which is necessary to achieve climate neutrality targets. It aims for a sustainable built environment characterised by building material efficiency and reduced climate impact through circularity principles in the whole life cycle of buildings. It is expected that the launch of a new comprehensive Strategy for a Sustainable Built Environment in 2024 should guarantee coherence across policy areas, such as construction and demolition waste, climate, energy efficiency, accessibility or digitalisation.

• Waste Framework Directive (WFD)

  this sets the basis for waste management, including the definition of waste, recycling, and recovery. According to this Directive, Member States were obliged to reuse, recycle and recover 70% of non-hazardous construction and demolition waste by 2020, and minimise waste generation.

• Energy Performance of Buildings Directive (EPBD) and Energy Efficiency Directive (EED)

  they both aim to achieve a fully decarbonised building stock by 2050. In particular, the revised EPBD will boost the Renovation Wave by setting up national building passport schemes to guide building owners during the renovation to reach zero-emission buildings. The revised directive also introduces a disclosure of whole life cycle emissions for buildings (“A requirement to calculate the life-cycle global warming potential of new buildings constitutes a firs step towards increased consideration of the whole life-cycle performance of buildings and a circular economy”).

• Level(s)

  is the European framework for sustainable buildings, providing a common language to assess their performance. It also offers an extensive tested system for measuring and supporting improvements from design to end of life of residential buildings and offices.

• Taxonomy regulation

  it defines economic activities aligned with the EU net-zero trajectory by 2050 and broader environmental goals.

• New Construction Products Regulation

  will enter into force in 2024 and will provide a common technical language to assess the performance of construction products. Circularity aspects are integrated to ensure that architects, engineers and construction companies can take informed decisions.

You interested to reead about Financial instruments and initiatives for implementing circular economy, Circular economy organisations or EU-funded projects related to circular principles in construction. Read it here!

Conclusion

As one of the largest contributors to emissions and waste generation, the construction industry holds immense potential for mitigating environmental impact while simultaneously fostering economic growth and social well-being. Embracing circularity means rethinking every aspect of the building process, from design to end-of-life considerations. It involves maximising resource efficiency, promoting material reuse and recycling, adopting circular business models, and leveraging digitalisation for improved tracking and decision-making. By prioritising circular construction, Europe can not only meet its climate targets, but also pave the way for a greener and more sustainable future.

Do you want to know read more about circularity in buildings? Check Expert Talk with Michiel Ritzen!