Cities are expanding and rapidly developing with increasing urbanization. Most growing cities have built environment consist of countless rich architectural and building traditions that have evolved overtime. Often these historical buildings and neighborhoods have contributed to the identity, tourism and economy of cities and nations. Thus, amid global discussions related to the emission and energy consumption reduction of the built environment, these buildings and neighborhoods continue to be marginalized in academia of built environment. Though there are many refurbishment approaches being explored to increase the energy efficiency and emission reduction of historic buildings, any intervention towards these buildings could compromise the heritage value, authenticity, and many more tangible and intangible disturbances. In such context, the concept of Positive Energy Buildings and Positive energy neighborhood/districts researched under the EU green deal initiative bring forwards the novel idea of energy sharing and energy flexibility. Thus, the research aims to investigate the potential of SPEN as a way out from the interventions made on such buildings or neighborhoods through utilizing the notion of aggregated mutual interaction between buildings explored under SPEN. Further, the study digs deep to understand which level of mutual interaction between existing and new buildings is sustainable in terms of the level of intervention made. Thus, research explores this notion under what potential energy efficiency and architectural- trade-offs the building must bear.