The building sector has grown into one of the primary causes of environmental pollution in the past few decades. The primary goal of this research is to promote sustainability, which will be advantageous to both the present and future generations. The primary target of sustainability, commonly referred to as green construction, is to minimize carbon dioxide emissions and water, energy, and waste generation. The main focus of this study is to investigate the properties of agro-waste as a partial cementitious material. In this study, the cob ashes of corn (CAC) and peel ashes of cassava (PAC) are substituted for cement in mortar to foster sustainability. To determine the oxide content and mineral traits of the sample, X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy (SEM) analyses were performed. Tests for consistency and setting time were conducted to assess the viability. Compressive strength tests, impact strength tests, tensile strength tests, flexural strength tests, and rapid chloride penetration tests were carried out to evaluate the durability properties. The statistical analysis was performed finally to figure out the results regarding the characteristics and behavior of the agricultural waste.