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The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site system boundary. This comparative building LCA comprises the product stage (including raw material extraction, processing, transporting, and manufacturing) plus transportation to the construction site (nodule A1–A4, according to standard EN 15804 definitions). In this study, GWP is primarily assessed with the exclusion of other environmental factors. Tally®, as one of the most popular LCA tools for buildings, is used in this comparative LCA analysis. In this study, the substitution of mass timber for a steel structure with a corrugated steel deck and concrete topping offers a promising opportunity to understand the GWP impact of each structure. Mass timber structures exhibit superior environmental attributes considering the carbon dioxide equivalent (CO2 eq). Emissions per square meter of gross floor area for mass timber stand at 198 kg, in stark contrast to the 243 kg CO2 eq recorded for steel structures. This means the mass timber building achieved a 19% reduction in carbon emissions compared to the functional equivalent steel structure within the building modules A1 to A4 studied. When considering carbon storage, about 2757 tonnes of CO2 eq are stored in the mass timber building, presenting further benefits of carbon emission delays for the life span of the structure. The substitution benefit from this construction case was studied through the displacement factor (DF) quantification following the standard process. A 0.28 DF was obtained when using mass timber over steel in the structure. This study provides insights into making more environmentally efficient decisions in buildings and helps in the move forward to reduce greenhouse gas (GHG) emissions and address GWP mitigation.

The impact of the building and construction sector on climate change is becoming more important and recognized. Multiple initiatives around the globe have been utilized to design and develop residential structures, aiming to reduce energy consumption and carbon emissions; yet, there are several barriers to effective construction processes. This research outlines the gaps and barriers encountered by key stakeholders that were engaged during the preconstruction phase of a three-story multi-generational low-impact Passive House in Fayetteville, Arkansas. Through direct observation and open-ended interviews, the primary data are collected, and secondary data from a comprehensive literature review are detailed to capture the challenges faced during different phases of the implementation of sustainable residential dwellings. This study highlights the limited knowledge and experience in sustainable building design as a common barrier among participants along with the insufficiency of the regulatory framework governing adopted building codes in Arkansas, in facilitating sustainable building design implementation. These challenges, among others, are then thoroughly examined, and recommendations to address them are described.