The research problem is summarized in the lack of sustainable applied vision in the field of architecture and urbanization to improve the environmental performance of architectural spaces and existing buildings despite the fact that many of them have a non-dynamic, plastic and environmental characteristics, and a gap between the theoretical and practical aspects.  The research focuses on activating solar energy techniques and their impact on solving energy problems with architectural spaces and rationalization of their consumption in existing buildings under the constraints of the status quo such as guidance and the effects of urbanization. Therefore, the research aims to study how to activate the applications of solar energy in architecture and the conclusion of design strategies and their application in a case study ( a local existing model ,the building of the guest house and conferences at Mansoura University ) and its environmental performance evaluation. By following the research methodology in the following order: • The theoretical study method through the study of architectural and architectural applications based on solar energy and its impact on the design of urban space and architectural cover (social- formally - environmentally - functionally). • Then the analytical approach to study and analyze a project that uses solar energy techniques in the design of the urban vacuum to produce design strategies that achieve a balance between sustainable environmental thought and architectural and architectural creativity. • The case study methodology was used to conduct an applied study of the design strategies derived on the building of Mansoura University Guest House, up to proposals and a design model that achieves an improvement in the environmental performance of the building and its measurements.