Simplified evaluation metrics for generative energy-driven urban design: A morphological study of residential blocks in Tel Aviv

For almost two decades, the Zero Energy Buildings (ZEB) standard has epitomized a commitment to the high energy performance of buildings. Nevertheless, the applicability of ZEB in hot climates is currently limited and furthermore, in light of the current limitations of traditional building energy modeling methods, new methods are necessary to effectively evaluate the energy balance potential of larger districts. To help bridge this gap, this paper introduces solar-based (both sun-hours and solar irradiation) and geometry-based prediction metrics to be used in optimization studies to evaluate the impact of urban morphology on the energy balance of residential blocks in hot urban contexts. These prediction metrics are derived from the simulated energy performance of 1,944 parametric variations of residential blocks in Tel Aviv. In a regression analysis, these metrics recorded high correlation with energy demand, energy supply and the balance between them. To test the applicability of these metrics for optimization, the RBFMOpt method is employed in a multi-objective optimization study of the energy supply and demand of a nine-block residential district in Tel Aviv. Detailed energy simulations are performed for the best non-dominated results from the solar and geometric optimization studies and compared to the non-dominated results from a full energy optimization run. The results indicate that these metrics - the solar and geometric area-weighted exposure and shading indices - can serve as effective energy performance indicators to inform early-stage morphological decisions making. This workflow promotes urban energy optimization towards more harmonized energy supply and demand driven approaches.