Mexico City s south urban periphery is now characterized by a growth pattern known as dispersed city, where urban dispersion and mixing of urban and rural activities, calls into question the rural-urban duality with which the territorial planning had traditionally treated this fringe. It also merits recognition for its possible role in promoting the sustainable development of this city, especially considering its future urban consolidation and its proximity to fragile natural systems. Thus, it is a space that should be planned keeping these new dynamics in mind, and where the regenerative development and design methodology, created under the paradigm of ecological sustainability, could be useful to define guidelines that orient the sustainable development of this area. This methodology recognizes the place itself and its unique character (essence), as the fundamental bases of the project, hence useful in defining the strategies for its regenerative development through architectural or urban projects. Even though the methodology proposes a framework for understanding the place of implementation recognizing its present patterns, it is not clear how to determine the core patterns that define the place’s unique character. To address this methodological void and define the essence of a place on the bases of an understanding of its patterns, and considering that, according to the theory of complex systems, the compression of relations amongst the elements of a system permits us to understand and determine those which are central to the present organizational dynamics; it has been identified the methodology called Influence Matrix which permits leads to the understanding of the relationallity of the elements of a system by detecting their own level of influence. Hence, the proposed objective was to design a methodological tool to detect the patterns of the southern urban periphery of Mexico City that could define the essence of a place located within this territory, and therefore promote its regenerative development. This methodological tool was based on a version of the Matrix of Influence, adapted to the analysis of patterns and on an expanded objective and subjective analysis from the Regenerative Development and Design methodology. Finally, the proposed tool was tested in the town of Santa María Tepepan, Xochimilco, to determine its essence.