The built environment has a profound influence on human cognition and emotional states. Given the partial overlap between motor cortical networks involved in spatial mapping and action understanding, the NuArch project investigates, through a novel neuroscientific (Nu) approach, how architectural (Arch) space modulates social cognition via motor representations. Using virtual reality (VR), behavioral measures, and electroencephalography (EEG), we explore the interplay between architectural and social experiences and their neural underpinnings within the motor system. Our empirical findings demonstrate how variations in architectural configuration significantly modulate EEG characteristics through embodied mechanisms. Specifically, navigation through narrowing architectures elicited increased motor activation in the left parietal cortex, followed by enhanced attentional neurophysiological markers in the dorsal premotor cortex during the processing of emotional body expressions. These results reveal that architectural features modulate motor and attentional neural dynamics through parieto-frontal mechanisms, establishing the fundamental role of motor representations as the neural bridge between spatial experience and social cognitive processes. Building on these neurophysiological foundations, we present a comprehensive framework of experimental scenarios demonstrating how NuArch principles can inform evidence-based design across diverse contexts. We examine applications for cultural institutions that optimize visitor engagement and social interaction, healthcare settings that support therapeutic outcomes and reduce patient anxiety, educational environments that enhance learning and collaborative processes, workplace designs that improve productivity and well-being, urban planning that fosters community cohesion, and specialized approaches for individuals with neurodegenerative and psychiatric conditions. The NuArch project establishes a transformative methodology for evidence-based architectural design, demonstrating how neuroscience-informed spatial configurations can actively support human flourishing rather than merely providing functional shelter. By revealing the measurable neurophysiological mechanisms through which architecture influences social cognition, this work positions built environment design as a powerful tool for enhancing human interaction, supporting mental health, and addressing contemporary societal challenges within our increasingly constructed world.