This study explores the theory that acceptable air quality can be obtained in office buildings with lower ventilation rates than those involving conventional designs. The study implemented two ventilation scenarios that satisfy ASHRAE Standard 62.1: VRP (Ventilation Rate Procedure) and IAQP (Indoor Air Quality Procedure). Both scenarios were tested in a new construction, high-performance office building. Based on results, we suggested an optimized combination of ventilation and air-cleaning requirements from an energy and air quality perspective. Through field study and mass balance modeling, we compared measured indoor concentrations, calculated whole building emission rates, and measured energy consumption for each strategy. Results showed that applying the IAQP with highly efficient air cleaning that targets all contaminants of concern -- coupled with reduced ventilation rates -- is a superior option that delivers both IAQ and energy savings. This study recommends an important application for designing according to the IAQP and demonstrates that careful design allows buildings to be ventilated at rates lower than called for in the VRP, thereby saving energy while also maintaining air quality.