The study examined the Evaluation and Integration of Green Building Materials (GBMs) for Sustainable Construction in Uganda with the aim of assessing their mechanical, environmental, and socio-economic performance and developing strategies for their adoption. The objectives were to quantitatively evaluate the mechanical and physical properties of selected local GBMs, to assess the environmental and economic viability of GBM-based structural systems through Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA), and to identify key perceived barriers and drivers influencing GBM adoption among construction professionals, ultimately developing a strategic framework for their integration into urban building codes. Laboratory experiments were conducted on stabilized earth blocks, bamboo composites, compressed agricultural panels, and recycled concrete aggregates to determine compressive strength, flexural strength, water absorption, thermal conductivity, and density. LCA and LCCA were performed to compare the environmental footprint and long-term costs of GBM-based systems relative to conventional materials, and surveys were administered to construction professionals to assess adoption barriers and drivers. The results indicated that the selected GBMs exhibited adequate mechanical and physical performance for building applications. Stabilized earth blocks demonstrated compressive strengths of 3.8–5.2 MPa, bamboo composites showed tensile strengths of 12–15 MPa and flexural strengths of 20–25 MPa, compressed agricultural panels had compressive strengths of 4.5–6.0 MPa, and recycled concrete aggregates retained 85–90% of conventional aggregate strength. Thermal conductivity and density tests confirmed that GBMs were lightweight and provided superior insulation, enhancing energy efficiency. Environmental assessment revealed that GBM-based systems reduced embodied carbon emissions by 48–52% and water consumption by 36–63% compared to conventional concrete. Life cycle cost analysis showed that although initial costs were slightly higher for some GBMs, lifecycle costs were lower due to reduced maintenance and extended service life, with SEB walls achieving a 17% reduction in total lifecycle costs. Surveys highlighted that key adoption barriers included limited technical knowledge (64%), insufficient design codes (58%), and inadequate market supply (53%), while drivers included high environmental awareness (72%), government promotion of sustainability (65%), and growing demand for energy-efficient buildings (60%). It was concluded that locally available GBMs were technically, environmentally, and economically suitable for sustainable construction in Uganda. The materials demonstrated sufficient strength, durability, and insulation properties, while GBM-based structural systems offered lower environmental impact and reduced lifecycle costs compared to conventional materials. The study also concluded that professional capacity, standardized codes, and institutional support were critical for widespread adoption of GBMs. Based on these findings, it was recommended that the government develop and integrate GBM standards into national building codes, implement pilot demonstration projects in different urban contexts, strengthen supply chains for local GBMs, provide professional training programs, introduce policy incentives and green certification schemes, and conduct public awareness campaigns to promote adoption. Continuous environmental and economic monitoring was also advised to ensure long-term sustainability and performance.