Circular Environmental Impact of Recycled Building Materials and Residential Renewable Energy

Building materials, due to their mass and energy-consuming production processes, drastically increase the embodied energy of construction. This study assesses circularity processes for the construction industry with a life cycle assessment (LCA) of a case study located in a large cosmopolitan city. The research concludes that a significant decrease in environmental impacts results from a shift to recycled materials in the construction phase, as well as from changing the landfill disposal method to recycling. In particular, it was found that the use of recycled building materials (such as recycled cement, metal, concrete, or glass) during the construction phase and recycling disposal methods lead to an overall decrease of impact up to 65%. This work also underlines the importance of circularity in renewable energy production systems. In both wind and solar systems, most of the environmental impact caused during the production phase are paid back during the second year of their life due to the energy gains of the renewable energy system. However, the recovery of metal depletion requires 667 years. This result provides evidence of the emerging need for integrating circular processes regarding recycling and reusing materials in construction and also in the energy-generating sector.