In this study, the researchers aimed to broaden the applications of unsaturated polyester resin (UPR) composites in the building field by incorporating surface-modified titanium dioxide (TiO₂) nanoparticles and reinforced chopped glass fibers within the UPR matrix. Specifically, the composites containing 4 wt.% TiO₂ nanoparticles and 30 wt.% chopped glass fiber exhibited remarkable properties of 46.1 kJ/m² in impact strength, 90.1 MPa in flexural strength, 78.8 MPa in tensile strength, and 121.5 °C in heat deflection temperature, which improve 207.5%, 80.3%, 62.5%, and 73.6%, respectively, when compared with the blank sample. Furthermore, the results of the corrosion resistance test showed that the composites performed poorly against polar organic and alkaline solutions, presented good corrosion resistance against acidic media, and behaved relatively stable in the salt solution.