The paper presents an integrated methodology for the sustainable energy retrofit of historic buildings, leveraging Scan-to-BIM workflows, Industry Foundation Classes (IFC) databases, and dynamic energy simulations. The approach addresses the challenge of balancing energy efficiency improvements with heritage conservation, since traditional retrofitting methods are often incompatible with such dwellings. The IFC model is generated from accurate 3D reality-based survey by automated processes, including point cloud segmentation and computational geometry techniques to enhance model accuracy and expedite the modeling phase. The IFC database is then enriched with material properties to enable energy assessment, testing interoperability with energy simulation tools. Applied to the historical case study of Villa Meschio in Treviso, Italy, the methodology compares different interior insulation and glazing strategies through dynamic simulations performed with Edilclima software. Results emphasize the effectiveness of the envelope retrofit, especially when integrated with adaptive shading solutions, in optimizing both winter and summer performance. Despite current limitations, the workflow addresses challenges related to interoperability between BIM models and energy simulation software. It finally contributes to the definition of integrated, data-driven procedures for sustainable retrofit interventions that respect the value of historic buildings.