In Jordan, residential buildings consume up to 48% of electrical energy, a significant amount of almost the half of energy goes for heating. Green roof is one of the passive techniques that improves energy performance. This paper examines the energy performance and Carbon Dioxide (CO₂) reduction of the green roof technology in the semi-arid Mediterranean climate of Amman by considering a typical apartment in Jordanian residential building as a case study. The effect of soil thickness, air gab and irrigation were determined for the performance of extensive green roof regarding to their plant. Malva Parviflora has been chosen for study. The base case model annual energy consumption has been determined by DesignBuilder software without a green roof installed. The result shows that installing extensive green roof saves annual energy consumption up to 14.25%.