The pervasive performance deficit in Nigeria’s public building infrastructure, characterized by high operational costs and poor occupant comfort, underscores an urgent need for adopting Sustainable Construction Practices (SCPs). However, the extent of their adoption and their tangible impact remains poorly documented. This study empirically assessed the level of SCP adoption, its impact on building performance, and the key barriers and enablers within Nigeria’s public sector. The research employed a descriptive survey design, utilizing a structured questionnaire to collect quantitative data from a sample of 381 construction professionals selected via a multi-stage sampling technique from the six geopolitical zones of Nigeria. The instrument, validated by experts and demonstrating high reliability with a Cronbach’s Alpha of 0.87, gathered data on a 5-point Likert scale, which was analyzed using descriptive statistics (mean, standard deviation) and inferential statistics (Pearson Correlation, Independent t-test). The findings revealed a moderate level of SCP adoption, heavily skewed towards economically pragmatic practices. A strong positive correlation (r = 0.81) was established between SCP adoption and an integrated building performance index, with high-SCP buildings demonstrating significantly superior performance, including over 30% greater energy efficiency, significantly lower operational costs, and markedly higher occupant satisfaction. The primary barriers identified were the perception of high initial cost and a critical knowledge gap, while targeted training and policy incentives emerged as crucial enablers. The study concludes that SCPs are a strategic imperative for enhancing public asset value and recommends policy reforms, including a mandatory green building code and revised procurement processes that prioritize lifecycle costing, to accelerate their adoption.