A single-family house was designed as a new middle-income green residential building in the Sultanate of Oman, according to criteria defined by the green building certification system EDGE (Excellence in Design for Greater Efficiencies), developed by the International Finance Corporation (IFC), which is a member of the World Bank Group (WBG). The design was accomplished through the free cloud-based tool of EDGE. With respect to a base design for the Sultanate of Oman, the green home design achieved savings of 40.86%, 20.22%, and 26.39% in energy, water, and materials (Embodied Energy), respectively. In addition, a saving of 35.48% in greenhouse gas (GHG) emissions was estimated. Based on the completed green building design, four green building-normalized metrics were used to quantify the efficiency of the base case and the design case in terms of the consumption of resources and polluting emissions. These efficiency metrics are: Carbon Emission Index (CEI), Energy Performance Index (EPI), Water Consumption Index (WCI), and Embodied Energy Index (EEI). Out of these green building performance metrics, the EPI is directly provided by EDGE, while the other three are introduced here as additional useful indicators that allow fair evaluations and comparison with other buildings, due to their less stringent dependence on the floor area or the number of occupants.