Working toward net zero light wood frame structures

In light wood frame construction, balancing acoustic performance while reducing the environmental impact of building materials is a challenge of increasing importance in the effort to decarbonize new construction. Floor-ceiling assemblies often rely on cementitious materials to increase mass, which contribute to higher global warming potential (GWP). Concrete is responsible for 6% of greenhouse gas emissions worldwide. This study focuses on common light wood frame construction types, including open web trusses, and wood I joists. For decades in the USA and Canada, concrete or gypsum concrete toppings ranging from 0.75to 1.5 inches over wood joists and sheathing have been the most widely used approach. This study aims to evaluate alternatives to cementitious toppings that offer reduced embodied carbon. Additionally, incorporating recycled or bio-based materials into acoustic assemblies can increase biogenic carbon sequestration getting closer to a net zero carbon impact. This work utilizes ASTM E90 and E492 testing to quantify airborne and structure borne acoustic performance and environmental product declarations (EPDs) and industry averages to determine the GWP of an acoustic assembly. Several light wood frame floor assemblies are presented and compared, highlighting those that standout as high acoustic performers with below average embodied carbon.