%0 Journal Article %T Net Zero Energy Building: A Case Study Using ECOTECT Software under Beirut Weather Conditions %A Fadl Bdeir %A Chadi Nasrallah %J Open Journal of Energy Efficiency %P 1-20 %@ 2169-2645 %D 2025 %I Scientific Research Publishing %R 10.4236/ojee.2025.141001 %X We investigated the concept of NZEB and applied it to a case study of a 100 m2 home in Beirut weather using Ecotect software. A number of passive design strategies, including building envelope, orientation, glazing, and shading, will be studied in the first segment to optimize the building’s energy efficiency. In the second segment, a renewable energy source will be used to cover the remaining load necessary to meet the NZEB criteria. Our research indicates that 192.5˚ is the optimal facade orientation to minimize solar gains throughout the summer. Double walls measuring 10 cm with a 4 cm air gap make up the perfect wall envelopes. The results of the glazing and shading study showed that windows with a timber frame, a low E coat, and an overhanging west façade with a 6 mm air gap would all help to lower the energy needed. 46% of the savings were realized. %K Green Buildings %K Net Zero Energy Building %K Passive Design %K Energy Efficiency %K Envelope %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=141367