Quantification of peak demand reduction potential of buildings is critical for demand response (DR) analysis in a microgrid environment. Due to the varying nature of electricity consumption throughout the day over different seasons, DR periods affect the energy savings and peak demand reduction potentials of a building in different ways. This paper investigates peak reduction potential of selected commercial buildings within a microgrid environment through the control of heating, ventilation, and air conditioning (HVAC) set point and lighting brightness adjustment. Building models are simulated in EnergyPlus and validated against monthly, daily and 30-minute building electrical consumption with the actual consumption from the smart meter data. The study is conducted over two different DR periods for a winter and a summer week to understand how time of the day and different weather conditions influence building peak demand. Results show that with the proper choice of the DR period along with the HVAC set point and the lighting brightness adjustments, significant hourly peak demand reduction can be achieved for different types of commercial buildings. Co-sponsored by: IEEE Power Energy Society Speaker(s): Saifur Rahman, IEEE PES, Montreal Chapter, Montreal, Quebec, Canada, Virtual: https://events.vtools.ieee.org/m/279386