Model-driven engineering efficiently manages complexity through high-level abstractions and model transformations, progressively refining models into executable code. However, current approaches require models to adhere to the same meta-metamodel, limiting their applicability to isolated ecosystems like Eclipse/Ecore or UML. The adoption of Building Information Modeling (BIM) has highlighted the need for transforming models across various life cycle phases. Yet, the fractured modeling landscape of BIM poses challenges as of existing solutions’ restriction on complying to the same meta-metamodel and supported modeling formalisms (e.g., Eclipse/Ecore or UML). We introduce a novel meta-metamodel-independent model transformation formalism, accompanied by a domain-specific modeling language for declaring transformation rules at the meta-model level. Our approach leverages a formalism-independent core language for on-the-fly establishment of meta-models, enabling meta-metamodel-independent model transformations. We validate our proposal through case studies in construction and software engineering, demonstrating its feasibility and generalizability.