Factors influencing existing medium-sized commercial building energy retrofits to achieve the net zero energy goal in the United States

Despite the increased awareness of benefits and opportunities resulting from energy retrofits, there is a lack of information regarding the factors influencing the success of energy retrofits–especially deep energy retrofits–aiming to achieve a net zero energy goal. The aim of this study is to identify factors and variables that could contribute to the successful implementation of energy retrofit measures in buildings with the goal of achieving net zero energy. A database of 34 small- and medium-sized commercial building retrofit projects was developed for this analysis, which was derived from the New Buildings Institute’s Net Zero Energy Building Database. Five factor categories were investigated: physical, technical, environmental, economic, and policy. A total of 11 variables from the 5 categories were analysed. The results show that success stems from a combination of certain variables: the number of floors, the climate zone, and the building cost. In general, the results indicate a trend: compact buildings with a construction cost range between $19/m2 and $42/m2 in a mild climate have a higher likelihood of achieving a net zero energy goal. Also, the analysis provides new evidence toward the importance of understanding a building’s physical characteristics in an existing building energy retrofit.