Refactoring legacy systems is essential to maintain and modernize aging codebases, but traditional refactoring tools are often limited by language specificity and lack extensibility. This thesis introduces property-based Abstract Syntax Trees (ASTs), a flexible intermediate representation aimed at enhancing the language-parametric capabilities of refactoring tools. By leveraging Tree-Sitter, a parser generator that creates parsers that produce generic, property-based ASTs, this research adapts Renaissance, an existing industrial refactoring tool, to support multi-language extensibility with minimal additional effort. The adapted tool demonstrates equivalent functionality across C++, Java, and Python, maintaining features such as pattern matching, code rewriting, and placeholder handling. Experiments were performed, including experiments with exercises on an open-source repository, in order to highlight the practical benefits, extensibility, and limitations of this approach. This adaptation aims to showcase the feasibility of using property-based ASTs in enabling language-parametric tooling. This work lays the foundation for more centralized, cost-effective, and scalable tool development for industrial software refactoring.