Experimental buildings on university campuses require a substantial amount of electricity and gas, highlighting the significant potential for enhancing demand flexibility through advanced demand-side management strategies. However, there is a paucity of holistic analyses of demand flexibility specifically targeting experimental building types due to the complex segments of experimental devices and corresponding usage patterns. Thus, this paper proposes a statistical method with the real-life questionnaire survey for quantifying the flexible load in an experimental building for participation in demand response (DR). In this study, we examine the flexible loads provided by the experimental equipment and Heating, Ventilation, and Air Conditioning (HVAC) systems through analyzing the recorded energy usage data of the building energy management system (BEMS). In our analysis, we standardized the daily energy consumption patterns of typical laboratory rooms in the experimental building, taking into account variation between weekdays and weekends within the university setting. Furthermore, to quantify these flexible load resources in each room, a questionnaire survey was designed to evaluate the willingness of lab managers to implement load shifting and load reduction during peak hours. As demonstrated by the case study of an experimental building, the results indicate that it is highly feasible to modify equipment usage patterns to reduce peak load demand driven by economic incentives.