With technological advancement in the process of acceleration and the growing use of increasingly evolved computer resources, parametric software brings an apport to the process of development and execution of architectural and engineering projects, providing greater flexibility and rationality in design decisions. These tools allow the design solutions to be changed at any time without compromising the model as a whole and make it possible to explore design alternatives from a common base, expanding the range of possible solutions. For example, Rhinoceros, Archicad and Revit are some of the most used parametric modeling software, with emphasis on Rhinoceros and its Grasshopper plugin, which integrates advanced environmental and energy analysis features. This article presents the case study “House of Mirante”, located in Monforte, Alentejo, where climatic and thermal simulations were used to help optimize the project, demonstrating how parametric software can assist the architect in sustainable and efficient choices still in the design phase.