The cogeneration will be an always present concept in the forms of energy conversion in the future, since it proposes to optimize the use of the energy resources. The system specification goes primarily through a technical economic analysis, where all the investments and operational costs are quantified for minimizing the cost of the produced energy. In the transformation of conventional systems for operation in cogeneration mode, there exists the necessity to estimate of electric and thermal consumption by these, so that the cogeneration system can be planned and thus displace the electric energy that would be used by the conventional systems. This works develops a methodology for estimating the electric and thermal load profiles, month by month along the year, from the few normally available data. For the electric profile, annual consumption data of electric energy measured at PUC-Rio, every 15 minutes in period of one year, has been used to validate this methodology. For the thermal profile, a methodology was developed; it discusses how the consumption of thermal energy can be estimated from values of ambient temperature, internal thermal loads and solar radiation incident on to place. Due to little data availability a comparison of the average solar radiation calculated by the proposed methodology and the one which is usually available in the literature, is done for a typical restaurant located in Albuquerque - United States.