Symbiotic Circularity in Buildings: An Alternative Path for Valorizing Sheet Metal Waste Stream as Metal Building Facades

This study suggests an alternative approach to valorize non-hazardous industrial solid waste flow into construction materials, in particular as metal facade systems by quantifying the creative reuse of consistent and predicated sized scrap metal cutouts (known as Offal) that were generated from the automotive sheet metal stamping and blanking manufacturing processes. This study is an expansion on two papers presented at the 10th International Conference on the Environmental and Technical Implications of Construction with Alternative Materials (WASCON). Automotive sheet metal waste stream was transformed into two novel building facade system designs and a “cradle to gate” Life Cycle Assessment was carried out to analyze their environmental impacts and its resultant effect on design, manufacturing and economy. A Material Design Circularity Factor was introduced to compare both facade systems. Design #1 had greater impacts for all indicators except for operational energy due to the possibility of infiltration. Economically, design #1 had almost double the savings of design #2 at approximately four million dollars annually. The avoided carbon emissions made it evident that the creative reuse of Offal had significant environmental impacts. The two facade systems avoided 7.8 and 5.3 million kg CO2-eq. of greenhouse gas emissions for design #1 and design #2 respectively. Industrial Symbiosis is a viable concept that can lead to the adoption of circular economy principles to activate reuse over recycling for industrial by-products, which was promoted by creativity, saved manufacturing energy and the reduced costs of production of construction materials. This study proved that reusing automotive metal scrap for building envelopes is environmentally optimal and economically affordable.