Evaluating Urban Forms for Comparison Studies in the Massing Design Stage

Abstract

We introduce five performance indicators to facilitate the comparison of urban massing design in the early design stages. The five simple indicators are based on existing studies and cover three main performance areas that are sensitive to urban form changes: solar, ventilation, and connectivity potentials. The first three indicators—the non-solar heated façade to floor area index, daylight façade to floor area index, and photovoltaics envelope to floor area index—measure the solar potential. The frontal area index measures the ventilation potential and the route-directness index measures the connectivity potential. The indicators are simple to use, as they only require urban geometry data for their calculation. We demonstrate the indicators in two case studies; variations in the values of these indicators show that they are sensitive to urban form changes and can be used in comparative studies to identify better performing urban forms among massing designs. We implement the indicators as an open-source Python library, Pyliburo, that designers and researchers can readily access and integrate into their existing design workflows. Keywords: performance-based urban design; performance indicators; connectivity; urban ventilation; solar analysis