Sustainable construction is increasingly recognised as a critical pathway for addressing environmental degradation in developing nations experiencing rapid urbanisation and resource constraints. This paper presents an integrative conceptual synthesis of sustainable construction practices and language mediation as complementary drivers of environmental sustainability. Drawing on a narrative review of 45 peer-reviewed journal articles published between 2013 and 2025, the study examines low-carbon construction materials, climate-responsive design strategies, and communication processes that influence public perception, policy legitimacy, and community participation. The findings indicate that while eco-friendly materials such as stabilised earth blocks, bamboo, and agro-waste composites offer substantial environmental and economic benefits, their adoption is strongly shaped by linguistic framing, cultural narratives, and inclusive communication. Language mediation emerges as a critical mechanism for translating technical knowledge into socially meaningful and widely accepted practices. The study concludes that integrating sustainable construction with effective communication enhances material acceptance, institutional support, and long-term environmental outcomes. By positioning architects and linguists as collaborative agents, the paper advances an interdisciplinary framework for promoting environmentally sustainable development in developing nations.