sustainability Article Towards an Adaptation of Efficient Passive Design for Thermal Comfort Buildings Ghada Elshafei 1, * , Silvia Vilcekova 2, * , Martina Zelenakova 2 and Abdelazim M. Negm 3   Citation: Elshafei, G.; Vilcekova, S.; Zelenakova, M.; Negm, A.M. Towards an Adaptation of Efficient Passive Design for Thermal Comfort Buildings. Sustainability 2021, 13, 9570. https://doi.org/10.3390/su13179570 Academic Editors: Nyuk Hien Wong and Paulo Santos Received: 25 June 2021 Accepted: 10 August 2021 Published: 25 August 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Department of Architecture, Faculty of Engineering, Minia University, Minia 61519, Egypt 2 Institute of Environmental Engineering, Faculty of Civil Engineering, Technical University of Košice, Vysokoškolská 4, 04200 Košice, Slovakia; martina.zelenakova@tuke.sk 3 Department of Water and Water Structures Faculty of Engineering, Zagazig University, Zagazig 44519, Egypt; amnegm@zu.edu.eg or amnegm85@yahoo.com * Correspondence: ghada.elshafei@mu.edu.eg (G.E.); silvia.vilcekova@tuke.sk (S.V.) Abstract: This paper discusses the effect of various climatic conditions that pertain to passive design measurements and their relationships with building configurations to improve indoor thermal comfort based on the different climate zones in Egypt to support Egypt’s sustainability agenda 2030. We find the most appropriate design settings that can increase the indoor thermal comfort, such as building orientation and shape. These settings can be modeled using DesignBuilder software combined with Egyptian meteorological data. This software is used accompanied by computational fluid dynamics to numerically assess the outcomes of different changes, by simulating indoor climate condition factors such as wind speed and temperature. Natural ventilation simulations were performed for four different shapes to create comprehensive dataset scenarios covering a general range of shapes and orientations. Seven scenarios were optimized to put forward a series of building bioclimatic design approaches for the different characteristic regions. The results indicated that the temperature decreased by about 3.2%, and the air velocity increased within the study domain by 200% in the best and the worst cases, respectively, of the four different shapes. The results of the study gave evidence that the configuration of buildings, direction, and wind speed are very important factors for defining the natural ventilation within these domains to support the green building concept and the sustainable design for a better lifestyle. Keywords: green building; climatic regions; thermal comfort; DesignBuilder; natural ventilation; building geometry; Sustainability 1. Introduction The idea of green building is gaining popularity in different countries. Green building is an idea that seeks designs for buildings that are compatible with the environment and resource conservation over their lifetime [1]. These objectives expand and complement the economic, utility, durability, and comfort concerns of classical building design. Green buildings are intended to minimize the total undesirable effects of environmental building on human health and the natural world. Green buildings utilize electricity, water, and other resources effectively, preserving the wellbeing of the inhabitants and increasing the efficiency of the workers. Additionally, green buildings eliminate waste, emissions, and deterioration of the atmosphere, which enhances the air quality for environmental protection [2]. This research focuses on thermal comfort, which, particularly in the hot–arid envi- ronment, plays a major role in all building sectors in Egypt. It has a significant effect on buildings’ indoor temperature and hence on energy use. It may also be represented using the Physiologically Equivalent Temperature (PET) and up-to-date thermal index [3]. PET is regarded as an important method for evaluating thermal comfort in various climates [4]. It depends on human characteristics (gender, age, dress, activity) and natural conditions Sustainability 2021, 13, 9570. https://doi.org/10.3390/su13179570 https://www.mdpi.com/journal/sustainability