Sonbol faraj mohammadi - Architecture Engineer, M.A, Department of Architecture and Art, the University of Guilan
Rozhin Eskandari - Urban Programmer, M.A, Islamic Azad University, Hamedan Branch

Despite the efforts made and much of the dialogue on sustainable development and ecological design in professional associations, environmental qualities of our great city is faced with increasing losses for reasons including lack of a comprehensive policy for environment .clear absence of concepts and principles associated with sustainable solutions, lack of knowledge in deterioration of the current conditions of the environment that many employers, planners and designers suffer from, should be added to above reasons. This paper aims to emphasis on environmental considerations through providing principles for designing urban streets in order to achieve stability and vitality of life in these urban areas. Improvement of urban streets needs a comprehensive approach in relation to the programming, management and urban space designing. Design practice for urban areas has a leading role, because it can make a place more balanced and self-sufficient in terms of resources. It can create a more vibrant place for living. Regarding to this, we would present three general principles: first; make an environmental regulation in an ecological context secondly; considering the constraints of energy consumption, and finally; Prioritizing the restoration, repair and recycling rather than widening and construction. These principles can improve the physical quality of urban sustainability and livability of cities and streets. Then after the overview of the problems and difficulties in Tehran's streets, as the case study, we would organize those difficulties according to the above-mentioned principles

City streets, environmental concerns, sustainable design, livability, Tehran