Climate change and rapid urbanization pose significant challenges to urban sustainability, particularly through the Urban Heat Island (UHI) effect, which is severe in the Mediterranean region. This area faces heat extremes, reduced precipitation, and increased cooling energy demands. Addressing microclimates in urban design is critical for improving thermal comfort and resilience. This research focuses on Madrid’s Picazo neighborhood, which has aging buildings and a vulnerable population. The study examines how microclimates, energy efficiency strategies, and urban morphology interact under summer conditions, predicting a 2.8 °C rise in extreme summer temperatures by 2050. Using calibrated ENVI-met simulations, the research evaluates façade solutions, finding Grey ETICS improve thermal comfort compared to White ETICS. It also highlights the role of shading, natural ventilation, and avoiding low wind-speed areas in new public residential buildings. Based on these findings, the study proposes guidelines to optimize façade materials, enhance ground-floor designs, and implement urban strategies to improve outdoor thermal comfort and urban resilience.