The aim of this research is to explore the effect of Vertical Greening Systems (VGS) on improving indoor environment quality and rationalizing energy consumption in residential buildings and consequently suggest a valid design guideline aiding the designer towards successful Eco-building realization. Vertical Green Walls(VGS) are considered one of the ideal solutions for treating existing buildings to increase thermal insulation and control the amount of heat gain through the outer envelope of the building, imp the thermal comfort, and re energy consumption. Moreover, such treat benefits in other ways such as absorption of carbon dioxide, release of oxygen and impact positively on humidification as well as improving building elevations external look. To measure the positive effect of VGS green walls, a computer simulation of applying green walls to an existing building was done, different types of VGS were compared with their different components and their effect on building indoor temperature, the ability and resistance to heat transfer, and the amount of carbon emission released to the atmosphere. A comparison was conducted to explain the difference between the original building status and the one after adding the VGS green walls. Finally, the research reviewed the results of simulation and effect ratios for several types of VGS walls, compared with the original wall, as well as with the addition of internal insulation. That final comparison associated with measuring weights was used to form design guidelines to help designers in choosing the proper type of VGS for each treated building in hand.