An environmentally friendly one-pot method was designed after the percolation approach for avoiding the grafting of molecules to the cellulose surface or the functionalization of the inorganic filler, silica nanoparticles. The key step of this work is using the solvent exchange strategy  for not drying the cellulose matrix, keeping the voids of biopolymer net to host the inorganic nanoparticles. The surface modification of cellulose by this method allowed the observation of its macroscopic hydrophobicity providing compatibility with the inorganic reinforcer up to 50 wt % registered by SEM images. Even when no contact angles of the samples were measured, we can say that the nanocomposite itself shows hydrophobic behavior hindering the fungal growth, thereby demonstrating high capability to use this material in exteriors such as building façades or as thermal insulator fillers, even when the material is not an aerogel.