In the Mediterranean and North African regions, traditional vaulted roof forms have been widely used due to their significant influence on enhancing thermal indoor conditions. This research parametrically investigates the thermal performance of vaulted roofs, seeking a better understanding of the reciprocal relationship between the solar irradiance received by these roofs and the resulting energy consumption in the hot-arid city of Aswan (23.58 degrees N), Egypt. The methodological procedure is realized through two phases. The annual simulations of solar irradiance and energy consumption are carried out in the first phase, where the quantitative performance of 2310 different cases are predicted in terms of six vaulted roof forms against eleven key influencing variables. The unsupervised technique of Principal Component Analysis is used in the second phase to reduce the higher dimensionality of the resulting dataset and extract important information from newly established orthogonal principal components. The outcomes of this work aim to provide architects and practitioners with an optimized dataset to use in the design and application of vaulted roof forms and support decision makers addressing the development strategies by providing essential data for setting regulations of newly built environments in harsh hot-arid contexts. (C) 2019 Elsevier Ltd. All rights reserved.