Urban Design Guideline Related to Physical Density Focusing on Solar Right of Residents – Case Study: Yousefabad Neighborhood, Tehran

This research develops an urban design guideline related to physical density with a focus on ensuring residents’ solar rights in dense residential neighborhoods. Taking the Yousefabad neighborhood of Tehran as a case study, the study explores how morphological parameters such as building height, spacing, and orientation influence solar accessibility, daylight performance, and energy efficiency. The research adopts an applied and quantitative approach, integrating urban morphology analysis, 3D modeling, and solar simulation using CityEngine, Rhino, and Grasshopper (with Ladybug and Honeybee plugins). Solar radiation, sunlight hours, and sky view factor were analyzed across three spatial scales — macro (neighborhood), meso (block), and micro (building) — under existing, approved, and optimized development scenarios. The optimization process employed a Genetic Algorithm (GA) to identify configurations that balance density with solar equity. Findings indicate that while densification reduces sunlight exposure, optimized morphological patterns can restore balance by enhancing radiation distribution, daylight quality, and sky visibility. The study concludes with a set of multi-scale urban design guidelines aimed at promoting energy-efficient, solar-responsive, and equitable urban forms in Tehran’s high-density contexts. Keywords: Solar Right, Energy Efficiency, Urban Morphology, Genetic Algorithm, Urban Design Guideline, Yousefabad, Tehran