ID Chair Concept develops the office chair as a configurable platform rather than a fixed model. A shared structural core supports interchangeable backrests, mechanisms, armrests and bases, allowing differentiated comfort within a coherent visual system. The project separates performance from appearance, making ergonomics adaptable while maintaining formal consistency. Through this modular logic, the chair responds to varied working postures and contexts without multiplying typologies, aligning industrial efficiency with individual calibration.