Life cycle cost analysis of energy-efficient buildings subjected to earthquakes

Abstract

A new life cycle cost (LCC) analysis method is presented to evaluate the long-term cost-effectiveness of energy-efficiency features in buildings by accounting for the future costs associated with earthquake-induced damages in such features. Buildings situated in a seismic zone are possibly attacked by earthquakes over lifetime and their nonstructural elements such as energy-efficiency features may suffer from various levels of damage, requiring repair or replacement to restore a satisfactory level of building energy efficiency. However, existing LCC analysis methods have overlooked such earthquake-related cost, potentially leading to unreliable cost-effectiveness assessment of energy-efficient buildings. To address this problem, we propose a method to rigorously quantify the expected cumulative future cost due to the repair/replacement of earthquake-damaged energy-efficiency features and then integrate this cost into the LCC analysis. The new method is illustrated using a medium-sized office building located in a high seismic region with a Mediterranean climate. Costs associated with the initial installation as well as future energy consumption, environmental impacts, and seismic damages of two alternative types of window assembly with different levels of energy efficiency are calculated and compared. It is found that, with seismic damage cost considered, the cost-effectiveness of energy-efficiency features can be noticeably reduced and, equivalently, the payback time for building energy efficiency investment is prolonged.