Application of Life Cycle Energy Assessment in Residential Buildings: A Critical Review of Recent Trends

Abstract

Residential buildings are responsible for a considerable portion of energy consumption and greenhouse gas emissions worldwide. Correspondingly, many attempts have been made across the world to minimize energy consumption in this sector via regulations and building codes. The focus of these regulations has mainly been on reducing operational energy use, whereas the impacts of buildings’ embodied energy are frequently excluded. In recent years, there has been a growing interest in analyzing the energy performance of buildings via a life cycle energy assessment (LCEA) approach. The increasing amount of research has however caused the issue of a variation in results presented by LCEA studies, in which apparently similar case studies exhibited different results. This paper aims to identify the main sources of variation in LCEA studies by critically analyzing 26 studies representing 86 cases in 12 countries. The findings indicate that the current trend of LCEA application in residential buildings suffers from significant inaccuracy accruing from incomplete definitions of the system boundary, in tandem with the lack of consensus on measurements of operational and embodied energies. The findings call for a comprehensive framework through which system boundary definition for calculations of embodied and operational energies can be standardized.

A Comprehensive Framework for Standardising System Boundary Definition in Life Cycle Energy Assessments

“…LCEA is a version of the LCA that only accounts for energy usage at all stages of a building's life cycle [6,24]. In this approach, the total energy performance of a building is quantitatively assessed considering both operational and embodied energies.…”

“…Currently, the literature is lacking such a comprehensive framework. This lack is reflected in the findings of recent studies that reported variations in the results of life cycle energy assessment (LCEA) analyses [22][23][24][25][26]. In a recent study, Pan and Teng [26] conducted a holistic literature review analysis of 244 case studies, aiming to quantify potential variations in embodied energy calculations.…”

“…The results showed that significant variations may stem from the choice of method for embodied energy assessment, i.e., a 200% increase from process-based to hybrid method. In addition, the varied approaches of studies to account for the effects of parameters influencing the assessments of embodied and operational energy can be critical in varying LCEA results [23,24]. For instance, Pan and Teng [26] found that unclear descriptions of system boundaries for including cradle-to-gate and cradle-to-end of construction embodied energy may cause a 9.2% variation in the achieved results.…”

Thermal Performance Assessment of Walls Made of Three Types of Sustainable Concrete Blocks by Means of FEM and Validated through an Extensive Measurement Campaign

“…It allows us to select the most ap-propriate systems that will provide an efficient and sustainable design reducing this way the building's Heating Ventilation and Air Conditioning (HVAC) loads. By designing a sustainable building method, the use of energy, water, land, and raw materials must be minimized, reducing emissions, pollution, waste and also the running costs of any building [7]. A sustainable construction should be energy efficient and cheaper to run, durable, and made of environmentally friendly materials so waste during the whole construction period should be considered, for both cost and environmental impact.…”

Carbon Dioxide Footprint and Its Impacts: A Case of Academic Buildings

“…Across the world, the energy requirement is increasing rapidly due to the attraction of urbanization facilities and the human population [6][7][8]. The world's largest CO 2 contributors are buildings, as the current building structures are demolished and rebuilt as huge buildings like skyscrapers to accommodate the population in urban areas [9][10][11].…”