This research focuses on the technologies that can help the architecture and building sector to overcome the issue of uncertainty when it comes to the performance evaluation of a construction. In the next chapters, a detailed literature review and two case studies lead to a conclusion of the today’s status of the building performance simulation tools and how they can be implemented in the design process. An overview is made makes of what is on today’s market regarding software programs that later narrows it down to the most accessible programs, but also on the ones that offer a wide variety of solutions to some of the most common issues nowadays.