This study explores the concept of urban heterogeneity in modern cities. Traditional planning and design methods tend to treat all areas of a city in a uniform way, applying the same urban codes throughout. However, in many cities, especially histori cal ones, different areas require diverse codes to maintain their heterogeneity, rather than enforcing homogeneity across the entire urban environment. In order to explore the heterogeneity in urban form, Duhok City in the Kurdistan region of Iraq is selected as a case study, which is characterized by a mix of traditional and modern architectural forms and implies the het erogeneity in urban form, although the municipal codes deal with it as a homogenous entity. Duhok presents a unique urban growth and transformation mechanism. It has its roots in a small town; over the period, the urban area gradually extended its geographic borders, integrating surrounding villages into its entity that have been transformed into parts of the city as urbanized villages. In order to reveal how the city's heterogeneous urban form resulted from old and newly developed parts and was influenced by the implicit and explicit urban codes. A mixed parametric approach is utilized, combining an objective spatial statistics analysis (Moran’s I) and visual analysis. The main contribution of the current study is providing a framework for investigating the heterogeneity in urban form. As the findings indicated, the urban form of Duhok City is characterized by being heterogeneous. Consequently, to preserve this identity while regulating growth, at least two types of codes should be applied to the development area. That will offer valuable insights for urban planners, designers, and policymakers in Duhok, providing practical strategies for managing urban growth while preserving its unique identity.
