Historical cities demonstrate a challenging complexity of urban and heritage properties, encompassing many layers of information. Traditional planning regulations fall short of dealing with this complexity with limited comprehension cast on the typomorphological relationships. This paper describes a heritage transect system that incorporates contextual characteristics and spatial richness. The proposed heritage transect scheme only addresses morphological aspects of the built environment. Utilising a 3D parametric approach, this study presents a computational method to analyse historical urban landscapes. This paper demonstrates the potential of typomorphological analysis in the context of planning historic urban areas to facilitate decision-making processes. It also outlines shows how the urban transect can be tailored to the unique heritage context, complemented by form-based code definitions specific to the historical environment in Mardin.