The feasibility study is crucial for decision-making in the investment stage of photovoltaic systems projects. A cost-benefit analysis for a project should not be evaluated solely in terms of money in-flows and outflows; it is important to consider other characteristics such as climate, solar irradiation, and the hours of sunshine in different spaces, as well as the electricity rates of the electricity supply company. Therefore, analyzing and simulating the performance conditions, both technical and economic, of photovoltaic systems is key. The objective of this study was to analyze the investment models in two types of photovoltaic systems: one integrated into the construction and the other conventional in a building in the Mexican Republic, considering ideal conditions, thus evaluating the energy efficiency in cities, as they consume around two-thirds of the world's energy and are responsible for 70% of global greenhouse gas emissions. The methodological proposal was to select a location, determine the predominant type of climate and collect data on solar radiation, the electricity supplier rates, the profitability for a cost-benefit analysis, and the inflation rates to determine the viability of a project that comprehensively covers the variables for decision-making.