Including daylighting strategies from early to the end in the building and urban design process is crucial when it comes to the compliance of environmental certification systems or when the aim is to simply create an interior or exterior space with sufficient access to natural light while still thermally comfortable. Therefore, in this paper, we are going to introduce and discuss a new tool that is an add-in for Autodesk Revit and newly developed by the authors to help architects or urban designers/planners to evaluate daylight condition of exterior or interior spaces by calculating different daylight metrics in different design stages. Since, in a BIM model, most of the information that is needed for daylight analyses are already included in the model, lots of time and human errors can be reduced by making direct communication between the BIM model and Radiance as a physically valid lighting and daylighting simulation software that works as the main calculation core for doing different types of daylight simulations in this add-in. Thus, by saving time and minimizing the mistakes and associated problems when exporting the model for analysis directly from Revit to Radiance and importing the results vice vers a, this new add-in makes its users free from using any other third-party software. The main goal of this add-in is to work as a supportive decision-making tool for those dealing with indoor or outdoor quantity and quality of daylight and its associate threats during the architectural design process. Moreover, its results can be used for other assessments such as when doing thermal comfort analyses or electrical energy consumption in a building. Therefore, it can be helpful for architects, urban designers/planners, and engineers in their everyday works.