The new Green Building Code impacts the design and construction of building systems, which are vital for energy consumption estimation, especially since electricity prices are of great interest to today's consumers. Through the integration of energy consumption and utility bills, this paper presents the results of the economic impacts of installing various energy efficient systems required by the Green Building Code. Energy consumption prediction models are developed using multiple regression statistical methods based on electricity data collected from 110 single-family houses located in Los Angeles, California, USA. These prediction models have found a significant difference in electricity consumption of a single-family house prior to the introduction of the code and after its introduction. In addition, life cycle cost analysis on two of the featured systems, photovoltaic system and hybrid water heater, discovered that consumers can pay off their up-front investments in state-of-the-art energy efficient systems and appliances and earn a profit within the stated life cycle time period. The findings provide useful guidelines for making initial monetary decisions in the residential building industry.