This study aims to incorporate building and demolition waste, including lime and crushed granite, as partial alternatives for cement and fine aggregates, respectively, and to devise a plan to reduce their environmental effect resulting from their extensive prevalence in substantial amounts. The use of lime in paste, mortar, and concrete has become a common practice to regulate the environment, save resources, and improve performance in various settings. The first stage of this study investigated the effects of replacing different proportions (0%, 15%, 25%, 35%, and 50%) of lime powder with cement on the physical and mechanical properties of mortar specimens over 7, 28, and 90 days. The next phase of the research examined the impacts of substituting varying quantities (ranging from 10% to 100%) of granite powder in 15 different mixes, while keeping a consistent water-to-binder ratio of 0.45. The last part of the study consisted of an examination of data from previous research on cement mortar and lime-modified cement mortar. This included testing on flowability, standard consistency, setting time, flexural strength, and compressive strength. The acquired data underwent a statistical analysis, which resulted in the development of equations that may predict the mechanical characteristics of changed cement mortar mixes. These equations also highlight the impact of certain physical qualities on compressive and flexural strength.