In sight of current low building renewal rates, the development of energy retrofitting activities for existing buildings emerges as a major challenge to reduce energy waste. External thermal insulation appears as an interesting solution. Trades such as wood and concrete construction must now turn to digital and collaborative planning tools to improve their efficiency and respond to this challenge. The ISOBIM project aims to contribute to the transformation of this sector by developing decision support tools integrated into a solution that fosters the digital engineering of retrofitting processes utilizing modular framing panels. The originality of the project lies in proposing an environment overarching optimizer models for nesting, along with a collaborative scheduling framework. The latter will work under constrained models of Lean logics and 4D simulation that will help validating overall results.