The vernacular historic cities can be defined as an ensemble of local needs and construction materials-based architectures which reflects local traditions and cultures. Very often adaptive processes for sustaining settlements such as the vernacular ones are based on both sustainable resources and cultural practices. This set of indigenous, ecological, biological, and cultural characteristics make vernacular historic cities valuable place for the valorization of local cultures and intangible heritage. Nowadays, dealing with the challenging task of heritage preservation in emerging countries, technologies are very often economically uncompetitive if used without the right methodology and a proper use. This study highlights the application of digital technologies for the documentation of historic city centers in fragile contexts such as global south countries by a deep case studies analysis of the Indian old cities of Ahmedabad and Jodhpur. The main aim of the research was to evaluate accuracy requirement and assess digital tools for heritage preservation end enhancement. By means of affordable use of digital technologies, the research stressed the existence of a strong relation between sustainable economy development and cultural heritage preservation even through capacity building activities carried out on field.