Numerous researchers point out that in the early stages of architectural design many significant decisions are taken to directly affect functional qualities, performance of the building, aesthetics, and relationships of the building with the natural environment and climate, even if there is no certain and valid information to create satisfactory design solutions. This paper particularly focuses on the early stages of architectural design and searches for the opportunities provided by Building Information Modeling (BIM) tools, in terms of the concept of performance analysis and form seeking. The study also includes case study implementations which visualize the early processes of architectural design with benefits of BIM under different conditions to evaluate its opportunities during these design processes. A few case studies have been implemented to reveal how new BIM tools can help designers in these stages. As a result of the implementations, it has been understood that BIM is a powerful early stages of architectural design tool; not for designing, but for supporting design.