This paper proposes a method to determine, through mathematical estimations, the electrical load profile and consumption patterns of buildings, which can be applied in Energy Management Systems (EMSs). In the first stage of the method, the architectural and operating information of the building was collected to integrate its real behavior into the proposed model. Such data were gathered via a walk-through visit around the building, an interview about staff's behavior, and the determination of characteristic demand values to identify the electrical loads of the building. The latter were categorized into general and independent loads according to their location, service, and number of users. Subsequently, the estimated load profile was validated with results of on-site measurements of the power consumption recorded in the main distribution board of a building on the campus of a higher education institution. Additionally, the influence of the hourly occupancy level on consumption patterns was determined. The results showed a close relationship between consumption patterns and hourly occupancy. The ranges of maximum and minimum demand of the measured and calculated data exhibited a high level of similarity. Furthermore, the proposed method is useful to identify the percentage of participation of different spaces and electrical loads in the total consumption of the building.