The introduction of the computer to the architectural design process have facilitated the possibility to examine a large number of design alternatives by allowing continuous variation between pre defined constraints. However, for the most part, evaluation and comparison of the alternatives is still handled manually in a linear fashion by the designer. This paper introduces a different approach to the architectural design process, which calls for a multithreaded or a non-linear design process. In a non-linear design process design directions and alternatives are generated, presented and evaluated simultaneously, and in real time. As an example for a non-linear design process the Generative Performance Oriented Design model and software tool (GenPOD) are presented and discussed. Moving towards non-linear modes of design arguably increases design creativity by allowing generating and evaluating a greater number and variation of design alternatives.