The Life Cycle Assessment of an Energy-Positive Peri-Urban Residence in a Tropical Regime
Urban settlements are home to the greatest levels of greenhouse gas emissions and energy consumption globally, with unprecedented rates of urban expansion occurring today. With the majority of global urbanization occurring along the periphery of urban areas in developing countries, investigation of 'green' building practices designed specifically for 'peri-urban' regions is critical for a low-emitting future society. This study assesses a state-of-the-art residence designed for a middle-class family of four residing in the peri-urban region of Bangkok, Thailand. The residence employs both demand-side management strategies and low-emitting energy supply technology to achieve energy-positive status. To elucidate the influence that key design decisions have on the life cycle sustainability of the home, several variants of the residence are modeled. A process-based life cycle assessment consistent with the International Organization for Standardization (ISO) 14044:2006 standard and following ReCiPe Midpoint life cycle impact assessment methodology is used to quantify the life cycle impacts per square meter of conditioned residence floor area for climate change (582 kilograms [kg] carbon dioxide equivalent), terrestrial acidification (4.01 kg sulfur dioxide equivalent), freshwater eutrophication (30.4 grams phosphorous equivalent), fossil depletion (362 kg iron equivalent), and metal depletion (186 kg oil equivalent) impacts. We model multiple scenarios in which varying proportions of Bangkok's peri-urban detached housing demand are fulfilled by the energy-positive residence variants. Under the best-case replacement scenario (i.e., 100% replacement of future peri-urban detached housing), significant reductions are achieved across the life cycle climate change (80%), terrestrial acidification (82%), and fossil depletion (81%) impact categories for the steel-framed, energy-positive residence.