A framework for parametric evaluation of urban growth strategies under climate change

Rapid population growth in metropolitan areas increases building energy consumption and exacerbates environmental problems, while climate change further intensifies these impacts. In this context, the study proposes a multi-criteria and quantitative evaluation framework to support sustainable urban growth strategies under current and future climate conditions, using Istanbul, a metropolitan city with a temperate-humid climate, as a case study. Within this framework, a total of 216 highly representative parametric urban form alternatives were generated based on urban density (FAR1, FAR2, FAR3), window-to-wall ratio (WWR: 20%, 40%, 60%, 80%), road width (10 m, 15 m, 20 m), and two main building typologies (High-rise and Scatter). These alternatives were comparatively evaluated using performance criteria including energy consumption (heating, cooling, total), outdoor thermal comfort (UTCI), and urban heat island effect (UHI). Simulation-based calculations were conducted using Ladybug, Honeybee, Dragonfly, and UWG plugins within the Rhinoceros/Grasshopper environment. Regression analyses were performed on the obtained outputs to reveal the statistical effects of design variables on performance criteria. The findings indicate that increasing outdoor temperatures in the future will make cooling-oriented design strategies inevitable. Urban density (FAR ratio) was identified as the most influential variable across all performance criteria. In addition, the best (H_F3R10W20) and worst (S_F1R20W80) performing scenarios were identified using the weighted sum method. The study provides a practical and multi-dimensional evaluation approach to support decision-makers in climate-compatible urban building and urban design.