Circular construction materials
Buildings and construction are responsible for 39 % of global carbon emissions, while construction works and materials alone represent 11 %. Although great strides have been made in operational energy efficiency of buildings, there is growing concern for embedded or upfront carbon - all that goes into material extraction, processing, transportation, and construction works. Construction materials account for half of raw materials used in Europe, while construction and demolition waste represent ⅓ of all waste - one of the largest waste fractions by volume in the EU. Building materials therefore show an enormous untapped potential for a circular economy.
Public authorities - as managers of large portfolios of real-estate assets, as custodians of urban infrastructure and as regulators and enablers through zoning and permitting - have a key role to play in implementing the circular economy in the built environment. Learnings from the working group show experiences of leading European cities in procuring, participating and piloting policies and projects for circular construction. While key hotspots for improvement have been identified, so have remaining barriers. We hope these examples will inspire other cities to join the transition.
The public buyers within the BBI working group share a common ambition in applying circular economy principles to public construction projects and supporting the growth of a local circular economy sector. The aim of these activities is:
- to keep existing materials in use and retain their value, thus avoiding waste,
- to stimulate market innovation for less resource-intensive materials (e.g. bio-based building blocks or low carbon concrete), and ultimately,
- to reduce the embedded carbon of construction materials and lessen the environmental impact of raw material demand.
ACTIVITIES OF THE WORKING GROUP
Working group members have conducted pilot projects on circular construction or demolition of infrastructure or buildings, addressing different challenges to circularity of construction materials across the value chain. These pilots include:
- Testing of digital tools for tracking material composition, quantity and quality (material passports/ buildings as material banks),
- Selective demolition of a hospital and several schools to recover contained materials and components
- Social urban mining approach of cooperating with social economy enterprises (focus on social inclusion and green jobs for un- or underemployed persons) to remove, separate and transform secondary construction materials
- Procurement requirements for life-cycle assessment(LCA) calculations, environmental cost indicators (ECIs) and environmental product declarations (EPDs) for the principle construction materials
- Creation of a ‘circularity index’ to compare tenders in procurement considering value maintained, e.g. of concrete infrastructure
- Municipal-led circular land mass coordination between all construction sites in the city
- On-site transformation of old concrete for new recycled aggregate
- Inclusion of reclaimed materials and components in new constructions or renovations (doors, technical ceilings, bricks, floor boards, furniture
Who was involved?
City of Vienna (Group lead)
City of Amsterdam
City of Budapest
City of Haarlem
City of Helsinki
City of Lisbon
City of Oslo
City of Paris
City of Porto
City of Rotterdam
City of Stavanger
City of Vantaa