Stefano IV stands out as the first ecologically responsible building in Villa Carlos Paz, integrating housing, offices, and commercial spaces on a mid-block lot. Its rectangular morphology is defined by a porticoed, regular, and modular white façade, whose main feature is a living wall that acts as a natural thermal regulator. The project combines passive design with active solar thermal systems and water recovery strategies, culminating in a social rooftop with a natural garden. It is an innovative architectural piece that prioritizes thermal inertia and biodiversity, establishing a new standard of sustainability within the urban environment.