Civil construction is considered a major generator of urban solid waste and one way to mitigate this problem is to invest in modular construction systems, making room for lean and sustainable models. This paper evaluated the potential of Sugarcane Bagasse Ash (SCBA) as composites, combined with the inclusion of expanded polystyrene (EPS) in the production of cement slabs applied to civil construction. For the partial substitution of Portland Cement (PC) the chemical characterization of SCBA by fluorescence and X-ray diffraction was carried out and its production used concentrations from 6.8% to 25.5% of SCBA. In the cementitious plate, tensile strength tests were performed for flexure tensile strength, water absorption and permeability, in accordance to Brazilian guidelines. The results demonstrated the use of SCBA in partial substitution of PC in the proportion of 6.8% and 13.6% with absence of fine sand and 17% with addition of fine sand, allowing its use in a clean, modular and dry construction technology. It is possible to conclude, therefore, that the industrial residue of SCBA can be used in substitution of PC and that the inclusion of EPS in the studied product’s formula increases its volume and decreases its apparent density.