The well-being culture and mental health landscape within Nigeria’s built environment remain under-explored, despite their growing significance in shaping sustainable urban and workplace ecosystems. This study examines the prevailing practices, perceptions, and factors influencing well-being and mental health, focusing on the socio-cultural and institutional contexts of the Nigerian construction industry. It highlights the impact of poor mental health and well-being culture in the Nigerian built environment by investigating the factors that influence these behaviors. A survey-based approach was employed, involving construction professionals, organizational leaders, and built environment stakeholders. Data was collected through structured questionnaires designed to reveal the impact of ignoring these mental health and well-being factors, their causes, and potential improvement strategies. Data was analyzed using descriptive statistics and exploratory factor analysis to uncover underlying latent variables. Preliminary findings indicate that the key perception well-being culture in the construction industry in Nigeria has four major factors—Institutional safeguards and policy efficacy, access to support systems and collaborative interventions, built environment impact and mental health stigma, and research and literature gaps. These findings provide actionable insights for promoting a well-being culture, with recommendations aimed at policymakers, organizations, and stakeholders within the built environment. The study emphasizes the importance of an inclusive, culturally sensitive approach to mental health advocacy, aligning with broader sustainability goals. By addressing the interplay between organizational practices, societal attitudes, and individual needs, the research contributes to fostering a healthier, more resilient workforce and a built environment that supports well-being for all.