Positive Energy Districts (PEDs) have emerged as a critical strategy to mitigate climate change and reduce urban energy consumption. By integrating renewable energy generation energy efficiency measures and smart grid solutions at the neighborhood scale, PEDs lower greenhouse gas emissions while enhancing urban sustainability and resilience. This innovative approach accelerates the energy transition by promoting decentralized, adaptable, clean energy solutions. This paper presents the outcomes of the Italian National PRIN project NETPLUS (Neighborhood Energy Transition: towards Positive energy Balance and Carbon Neutral Districts), which investigates PED development and performance through the definition and modeling of district archetypes. Focusing on a mixed residential district in Bari, the study develops specific archetypes for both residential and non-residential buildings to capture unique energy consumption patterns and operational characteristics. A comprehensive modeling framework was employed to simulate the district's annual energy demand, and simulation results were calibrated against multiple data sources—including actual building energy bills and other benchmarks—resulting in discrepancies below 10%. This level of accuracy confirms the model's reliability for evaluating energy performance and guiding retrofit strategies. Furthermore, the project assessed the potential benefits of combining energy retrofit measures with on-site renewable energy generation. In a retrofit scenario, on-site renewable systems could supply 57% of the district’s annual energy needs. The benchmark data and reference models derived from this study are highly applicable to the Mediterranean region and similar climates, underscoring the transformative potential of PEDs in achieving energy self-sufficiency and advancing decarbonization efforts.