Association for Public Policy Analysis & Management

Buildings are responsible for about 40% of the consumption of raw material and energy in the United States. Some buildings signify themselves as energy efficient buildings by getting certified with third-party rating systems such as Leadership in Energy and Environmental Design (LEED) and Energy Star. An increase in the number of green buildings suggests the continued interest in energy efficiency and sustainability in buildings. However, extant studies find that the actual energy savings of these green certified buildings do not live up to the designed savings. This discrepancy between the predicted and the actual energy savings is known as the energy performance gap. While existing studies have identified many driving forces for energy performance gap, little research has been done to compare them and investigate their relative importance.

This study makes three important contributions to the existing literature. First, we investigate the energy performance gap through a more comprehensive and systematic approach. Second, this study includes much larger number of buildings (more than 100 buildings), compared to normally 20-50 buildings in existing studies. Third, this study examines both LEED and Energy Star buildings and thus can compare the factors influencing the energy performance of these two types of green buildings.

This interdisciplinary study identifies and analyzes the organizational, behavioral and engineering factors responsible for the energy performance gap in LEED and Energy Star buildings. 117 completed surveys from facility managers in the United States were obtained in 2017. The top three reasons identified by the facility managers for the energy performance gap in green commercial buildings are (1) building occupants use more energy; (2) more occupants are added; and (3) there are failures with energy efficient technologies. The engineering, organizational and behavioral aspects contribute equally to energy performance gap, and emphasis on only one aspect is not legitimate.

Probit model analysis shows that green buildings certified with LEED or Energy Star are more likely to have tenant lease agreement to eliminate asymmetric information for new tenants, and Energy Star buildings are more likely to have sub-metering for air conditioning. On the other hand, LEED buildings are associated with factors that are more likely to cause less-than predicted energy savings after green-certification, such as lack of sub-metering for air conditioning and longer operation hours. Building characteristics such as reported occupancy rate, building type, ownership and location interact with the identified socio-technical factors.

This study adds to the existing discussion on energy performance gap by examining the relative importance/frequency of the reasons and factors as well as the heterogeneity of these factors among different types of buildings. After exploring various aspects of factors, the areas where action is required are identified. We propose several solutions to improve them in order to bridge the energy performance gap. Firstly, incentives should be provided to facility managers to keep them motivated to save energy. Secondly, energy consumption should be monitored continuously through commissioning, setting targets or energy performance contracting. Thirdly, occupants’ behavioral change should be integrated into the efforts to narrow the energy performance gap.