Urban planning regulations play a significant role in shaping the physical form of urban housing by defining construction requirements and guidelines for land-parcel utilization. These regulations influence building placement patterns and the organization of open space. Understanding their physical manifestations requires examining planning documents alongside the actual built outcomes at the parcel scale. This study comparatively analyzes the relationship between urban planning regulations and the physical form of housing in low-density residential areas of Shiraz, focusing on regulations associated with the 1972 Comprehensive Plan. The main research question is: How are urban planning regulations reflected in building placement patterns and the physical form of residential units?

Using a case study approach and comparative analysis, the research examines urban planning documents and regulations alongside field surveys of 20 residential units. The samples are classified into four groups according to their physical characteristics and building placement patterns. The analytical parameters include site coverage, building projections, positioning relative to parcel boundaries, entrance location, open space, courtyards, and light wells.

The findings reveal variations in building mass placement and open-space organization across the studied samples, associated with factors such as site coverage, building projections, and the arrangement of courtyards and light wells. The results emphasize the importance of examining urban planning regulations, parcel characteristics, and building placement simultaneously to understand the physical organization of housing. This approach provides a basis for evaluating the spatial implications of planning regulations and informing their potential revision.