ABSTRACT Green roofs are comprised of living vegetation that is installed on rooftops, serving as a sustainable architectural tool that offers numerous environmental, economic, and social advantages to the community. Green roofs have emerged as a prominent sustainable development strategy and architectural element in numerous urban centres worldwide. As for the effectiveness of green roofs in terms of boosting energy conservation in the Mediterranean climate of Amman, this research focuses on a standard medium-sized office building in Jordan. The main evaluation is carried out on the feasibility of enhancing the passive sustainability and energy performance of the building by applying extensive green roof technology. To determine the energy-saving potential, an annual energy demand in the absence of a green roof is estimated by a simulation program. In this paper, the analyses were performed in the form of parametric studies for assessing the impact of variation in soil depths on energy use, indoor temperature and carbon reduction. The study also indicates that green roofs can store heat and provide insulation enough to lessen the demand for comfortable temperature regulation indoors. The findings on energy savings indicate that energy consumption had reduced annually by up to 12 %. This means that largescale green roofs have the real opportunity to become an efficient sustainable passive design strategy for increasing the energy performance of office building in Amman climatic conditions.