<![CDATA[Additional material in the concrete mixture has several objectives such as Reducing Cement Content, Hydrating Heat, Reducing Shrinkage cracks, and Increasing Compressive Strength, etc. While natural waste such as bamboo, coconut fiber, and coconut shell as substitutes for concrete mixtures with the aim of reducing waste and green concrete. This paper aims to obtain an economic model for utilizing waste materials and reducing the amount of cement so that the concrete meets the elements of waste reduction and green. The methodology for making concrete mixture test specimens is the design of concrete mixtures modified with concrete mixtures with bio-enzymes and coarse aggregate substitution with natural bamboo waste, coconut fiber, and coconut shell at 15% volume of coarse aggregate. Test for 15x15x15 cm3 concrete cube at 28 days with a plan to reduce cement usage. The optimal percentage of cement reduction in the standard, bamboo, coconut fiber, and coconut shell design mixes was 30%, 24%, 18%, and 15% respectively. While the value of the cost savings for 1 m3 of normal / bio-enzyme concrete mixture is IDR 79,409, while for substitution of blends with natural ingredients is IDR 53,527; IDR 27,645; and IDR 14,704. The conclusion obtained is that economically using bio-enzymes in standard concrete mixes has a high value, while substitution with natural ingredients is intended to increase permeability and porosity.Keywords: Cost Saving of Concrete, Economic Value, Coconut Shell and Fiber, Bamboo, Bio-enzym.]]>
