Life Cycle Energy and Carbon Analysis of Single Family Residential Buildings: Atlanta Case Study

According to the united nations environment program (UNEP), by the increasing number of population in the urban area, there is an urgent need of city-level action on reducing environmental emissions. Based on the 2015 U.S. energy flow chart, buildings are responsible for around 20% of U.S. energy consumption and consequential environmental emissions. Therefore, there is a great need of a systematic national and regional observation and management plan for monitoring buildings' life cycle energy portfolio and their environmental impacts. The objective of this research is to study the residential buildings (1-story and 2-stories) built over decades, in the City of Atlanta and observe the trend of embodied and operational energy usage and the consequential carbon emissions over building's life cycle. In this research, embodied energy is the energy consumed by all the processes associated with the production of a building, from the mining and processing of natural resources to manufacturing, transport and product delivery. To this end, a process-based life cycle assessment (LCA) method has been utilized to calculate the embodied carbon and energy of buildings considering their construction methods and materials. For building operations, nationally averaged public datasets such as Department of Energy (DOE) and residential energy consumption survey (RECS) from U.S. energy information administration (EIA) were utilized. The preliminary results indicate that there is around 26% more embodied carbon associated with newer buildings. Also, the results indicate that 2-story buildings have around 11% less embodied energy per square footage, in comparison to 1-story buildings. Additionally, newer residential buildings consume less energy per square footage over their operational life span. The result of this research, combined with the analysis of other building types and infrastructures of the city, can then be used by policy makers and city planners to improve the sustainability and energy-efficiency of this metropolitan area.