The world’s plastic bag problem adversely impacts the environment daily. Plastic bags decompose after years, and some may take centuries, leading to pollution. Society relies on plastic bags for every task, which causes many problems for humans and aquatic life. Focusing on Sustainable Development Goal 12 (SDG 12), this research used waste plastic bags melted in a boilery to develop plastocrete to cast plastocrete paving blocks and roofing tiles. Compressive and split tensile strength tests were performed on plastocrete paving blocks, while a thermal insulation test was performed on roofing tiles in the Concrete Lab of our Department. The compressive strength test on plastocrete showed that it can easily replace concrete pavement blocks after giving good compressive strengths compared with concrete blocks. Being very low in tensile strength, plastocrete is not recommended for flexure members. The thermal insulation test results indicate that using plastic bags as roofing tiles decreases thermal conductivity compared with a controlled reinforced slab. Hence, it is concluded that plastocrete will help reduce pollution in the terrestrial and aquatic environment and can be an effective waste disposal solution. The plastocrete-led paving blocks and roofing tiles not only help economically but also help preserve nature and the environment from land pollution.