The research is concerned with studying the characteristics of Sustainable Architecture and Green Architecture, as a general research methodology related to the specific field of architecture, based on the differentiation between two generic concepts, Sustainability and Greening, to form the framework of the research specific methodology, where both concepts seem to be extremely overlapping for research centers, individuals, and relevant organizations. In this regard, the research tend towards searching their characteristics and to clearly differentiates between the two terms, particularly in architecture, where the research seeks understanding sustainable and green architectures, how they are so close or so far, and the possibility of finding common features between them that might make them as a one synaptic concept. The research problem focuses on that there is no clear differentiation between sustainable and green architectures, what causes a matter of confusion and unclarity in dealing with building projects what affects understanding processes and procedures during the progress of design, construction, and operation, within the whole building life cycle, and this leads to a defect in understanding the formation of building design, construction and operation. The research hypothesis shows that environmental and architectural indicators can form a mechanism to differentiate between sustainable architecture and green architecture. This mechanism depends on several elements that form, together, the hypothesis testing tool, and in turn, this tool will become a method to verify the hypothesis reaching accomplishing the goal of the research (formation of a theoretical framework) that enable to differentiate between sustainable and green architectures. The research methodology depends, also, on the effects of factors like economy, technology, welfare, and else, with focusing on the green growth and sustainable development as distinguished statuses in the two concepts, to reach establishing a comparative study and understanding their developing stages and clarifying the main differences between sustainability and greening, architecture wise, to form the elements of the theoretical framework to differentiate between sustainable architecture and green architecture. The theoretical framework is applied in two environmentally friendly architectural projects (case studies) to search their environmental and architectural features to reveal the availability of the features and characteristics of a sustainable building and a green building in each one of them.