Evaluating the Embodied Carbon Impact of Modular Construction through the Application of Zero-Loss Yield

Sammanfattning: Modular construction has recently become a renowned method of building. Many studies have been conducted on the benefits of modular construction; however, the available literature on its potential downsides is scarce. This study aims to evaluate the sources of potential embodied carbon inefficiencies of a modular multifamily residential building in San Diego, California. Quantity takeoffs and lifecycle analysis procedures were applied to collect data for the primary case study. Other similar projects were analyzed and compared to the primary case study. The results indicate that modular construction may experience an increase of embodied carbon of up to 10% compared to an identical, conventionally built project. A key driver of this embodied carbon inefficiency is an increase in structural material required to resist transport and placement stresses. Another primary driver is the doubling of walls that comes with the selection of highly standardized unit modules. Finally, the most significant driver of embodied carbon increases in this case study was the inefficiency of transporting fully assembled modules from the modular unit assembly factory to the construction site. If these sources of embodied carbon inefficiency can be mitigated, modular construction companies will be able to offer even more sustainable solutions to clients in addition to possible economic benefits and time savings often attainable from prefabrication.