Green roof technology has a history that predates the modern era. Many functions of green roofs utilized during human history are analogous to contemporary functions. The justification of the use of green roof technology based on a review of literature shows the multiple and documented benefits that these systems can impart to the urban environment. Green Roofs can save energy, reduce neighborhood temperatures, and protect human health. They have a strong regulating effect on the temperature of underlying roof surfaces and building interiors, reducing the energy needed for building cooling and the effects of the urban heat island effect. Keywords: Green Roofs, Energy Conservation, Heat Transfer, Insulation INTRODUCTIONConsidering rising energy price, its impact on consumption, creating motivation for efficiency and increasing its yield, moved researchers to investigate about plant's effect on energy consumption reduction. In addition, due to increasing in population and lack of adequate land for construction, building density in large cities has increased. This high density has caused lots of negative effects. The urban heat island effect that makes the average temperature in the city is higher than normal, is one of them. This increase in temperature causes an increase in energy consumption for cooling [1].

In the present age, one of the main elements in every country is information and its role in the development of countries. In such an era, universities are pioneers in development and knowledge production in which, academic libraries also play a significant role. In the design field, libraries that have long been synonymous with peace and tranquility are now considered as a place in which there should be a balance between quiet atmosphere and social dynamic mood. The aim of this study is to examine the evolution of spaces of academic libraries, which is constantly being changed as a result of technological advancements and alteration of old systems with new ones. Our research method includes reviewing similar domestic samples, conforming examples to library standards and examining the changing process of several foreign libraries over a period of time. The results of this study indicate that generally, modern libraries have fewer spaces for paper books and publications and individual study, instead, more spaces are dedicated to places for group studies and using computer. This change has influenced the function of the spaces, the relation between different parts of the library and people who use it.