Circular buildings: basics

Construction is one of the most resource-intensive sectors of the global economy. In times of increasing resource shortages and against the backdrop of the EU’s climate neutrality goals, the concept of circular building gains in importance. What’s it all about?

This approach aims to minimise resource consumption, prolong the lifecycle of buildings and reduce waste thereby making cities more sustainable in the long term.

Circular building is based on the principles of the circular economy aiming at reuse, repair, reclamation and recycling. This is different from the linear construction that consumes resources, manufactures products and produces waste. Construction methods and materials, which can be reused or recycled at the end of their lifecycle should be given preference or ideally be used exclusively. The concept banks on eco-friendly materials, renewable energies and innovative technologies.

The construction processes in circular building are carefully planned and oriented towards sustainability and resource efficiency. They differ markedly from traditional building methods and comprise several key stages:

• Modular design: buildings are designed to be modular meaning they consist of prefabricated components that are easy to assemble and disassemble.
• Flexibility: structures are flexible in design so that they can easily be adapted to future changes of use.
• Material selection: materials are carefully selected based on their durability, reusability and recyclability.

• Recycling and reuse: predominantly recycled and reused materials are used.
• Sustainable sources: materials stem from sustainable sources such as FSC-certified timber.

3. Preproduction

• Component manufacturing: as many components as possible are preproduced. This reduces waste and makes for more precise control of material quality.
• Standardisation: standardised components make it easier for them to be replaced and reused.

4. Execution

• On-site assembly: prefabricated modules and components are assembled at the construction site. This reduces construction time and minimises construction waste.
• Minimal interventions: construction processes are designed to minimise interference with the environment, e.g. by less soil sealing.

5. Use and maintenance

• Durability and flexibility: buildings are designed for a long lifecycle and simple adaptation to changed use.
• Simple maintenance: by using modular systems components can be replaced and repaired easily if needed.

6. Disassembly and reuse

• Disassemble rather than demolish: at the end of their useful life buildings are disassembled rather than demolished. This allows their components to be reused.
• Recycling: materials that cannot be reused directly are recycled and returned into the material cycle.
  
  
  

Disassembly and sorting: one of the biggest challenges is the disassembly of buildings and the clean-grade sorting of materials. Many conventional building methods make it difficult to reclaim materials without damage.

Quality retention: it is important for materials to retain their structural integrity and quality in reuse – proving a challenge especially for concrete and timber.

Logistics and warehousing: the logistics of reclaiming and warehousing reusable materials can prove complex and cost intensive. Often, materials have to be put into interim storage and transported requiring additional resources.

Standards and regulations: there are often regulatory obstacles because many construction standards and regulations are designed for the use of new materials. Reclaimed materials have to be used in compliance with these standards, which can require additional tests and certifications.

Market acceptance: reclaimed materials are not accepted on every market yet. A change in attitude among builders and investors is needed to fully recognise and take advantage of the benefits of circular building materials.

Circular building is a realistic way to make construction more resource-efficient and sustainable. Much is still in its infancy - there is often a lack of suitable materials, clear guidelines and practical experience. But the pressure to rethink is growing. With increasing political support, digital solutions and growing expertise, the circular approach is likely to gain momentum in the coming years. Those who take a closer look today will be better prepared tomorrow.

• Birk, T., & Eßig, M. (2024). Zirkuläres Bauen erfolgreich umsetzen. Landesanstalt für Umwelt Baden-Württemberg (LUBW). https://pd.lubw.de/10662
• Stricker, E., & Brandi, G. (2021). Bauteile wiederverwenden: Ein Kompendium zum zirkulären Bauen. Zürich: Park Books.