A Comparative Study of Safe Environment Toward Physical Design Theories and Providing a Design Guideline

The issue of security and defense of one's territories, as one of the effective factors in social sustainability, has been one of the primary human concerns until today. The importance of the impact of physical characteristics on the security of an environment has been the concern of many contemporary researchers. Theories such as defensible space, CPTED, safe growth, and psychological studies have each looked at the subject from a different innovative perspective. In this research, we have tried to facilitate the problem of designing a safe physical environment with a comprehensive approach to the subject, with a comparative study of existing qualitative studies and providing a design guideline in the framework of a different categorizing. Our assumption is that all the scattered parameters can be divided into the three primary factors of territorial behavior, natural surveillance and Image; that we can categorize the physical design requirements of a safe environment with logical reasoning by reviewing the historical-interpretive background of the subject and its qualitative analysis. For this purpose, we considered the rest of the scattered factors as a subset of one of these three general factors, and by classifying and labelling these items, we obtained the secondary subset factors of the primary factors. Finally, the secondary parameters of spatial structure, barriers were considered for territorial behavior, activity support and visibility for natural surveillance, access control for both, and quality, maintenance, and target hardening for Image. In Further studies, the degree of correlation and effectiveness of each of these factors can be discussed in the final result of designing a safe environment. This design guideline can be used as design basis as passive factors of a safe environment in urban design and neighborhood environments.