This paper aims to develop a morphological generator of urban rules of solar control based on a modeling approach of the Solar Bounding Box SBB. This is the optimum volume conditioned by both the urban rules of form and solar envelope rules. The urban rules are defined by the urban zoning regulations of a city. The solar envelope defines the largest volume that doesn't cast its shadows on neighboring buildings during critical periods of sunshine. The object here is to develop a digital tool for urban planning. This tool will assist planners for the drafting of urban morphological rules of solar control.