Evaluating Urban Forms for Comparison Studies in the Massing Design Stage

Abstract

We introduce five performance indicators to facilitate the comparison of urban massingdesign in the early design stages. The five simple indicators are based on existing studies andcover 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 areaindex, daylight façade to floor area index, and photovoltaics envelope to floor area index-measurethe solar potential. The frontal area index measures the ventilation potential and the route-directnessindex measures the connectivity potential. The indicators are simple to use, as they only requireurban 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 changesand can be used in comparative studies to identify better performing urban forms among massingdesigns. We implement the indicators as an open-source Python library, Pyliburo, that designers andresearchers can readily access and integrate into their existing design workflows. Keywords:performance-based urban design; performance indicators; connectivity; urban ventilation; solar analysis