The article presents the results of the study about the nature and multiple meanings of a sacred architecture, widely spread throughout the Venetian countryside: public oratory belonging to villa complexes. The study started from a very general question: what is an oratory and how is it possible to define and identify it with respect to other sacred buildings and churches? It was understood that only during the Council of Trent the oratory acquired a specific legal identity. Therefore, the Ecclesiastic Law has been studied as a precise tool to define the legal nature of the oratory of villa, declining it in the category of public. By restricting the study to the Diocese of Vicenza, the article defines the procedure foreseen for the construction of an oratory. It explains how the construction of sacred architecture in the Veneto was subjected to the contemporary disciplines of the civil and ecclesiastical legal regimes: Venetian Law issued in 1603 and a local codex called Costituzioni Sinodali. After careful examination of the legal instruments, the study clarifies the dynamics through which the three parties involved – the client, the civil power and the bishop – interacted in the construction process of an oratory. The article provides a summary of data obtained by the census of all the oratories built within the boundaries of the Diocese of Vicenza between the seventeenth and the eighteenth centuries.