The study briefly shades some light on the green architecture concepts through an analytical study for itsdefinition and the different green building rating systems.The study clarifies that implementing green measurements (regardless the total floor area) will results in reducing the energy consumption in buildings, and hence the GHG emissions. The study introducesthe Egyptian Green Building Council (EGBC), which has formulated theGreen Pyramid Rating System (GPRS) in 2009 as a tool for the green building assessment through its different categories. The study mainly focuses on applyingGPRS on ZeinabKhatoun Houseasa case study in old Cairo, in order to specifywhether the house is complied with the green buildings standards which will qualifies it for a green building certificate.