Felix Mallinder enhanced the BHoM/BHoM repository by introducing a Length unit attribute to the Thickness property within the Layer class, enabling the property to be treated as a length quantity with unit-aware validation. This update, implemented in C# using attribute programming and object-oriented design, improved data integrity and semantic clarity for downstream processes. By embedding unit semantics directly into the domain model, Felix laid the foundation for future unit conversions and consistent data modeling across the codebase. The work demonstrated a thoughtful approach to validation-ready data attributes, addressing the need for robust, unit-aware processing in engineering applications.