Though design for building performance is traditionally considered an evaluative act, current developments in the theory and technology of digital design are promoting new directions for performance-based models of design. This paper presents a theoretical basis for understanding the current shift in performance-based design and proposes a model of performance-based design in architecture, termed performative design. Automated processes related to the impact of environmental forces on form generation in digital design are the content of experimental processes upon which the paper reports. In the theoretical introduction the terms performative design and performative architecture are defined and discussed. Topics related to the current movement towards performance-based design in architecture, such as the role of topology, parametric design, associative geometry, and generative processes, are presented, and their implications for, and influence upon, performative design are discussed. An experimental design example in architectural design is demonstrated to illustrate various methodological issues in performative design.