The invention relates to a method for preparing a monolithic nanoporous silicate sol-gel material for modulating the pore size distribution for one single starting composition without the addition of a structuring agent, said method comprising the following steps: • a) synthesising a gel from at least one organosilylated precursor, the synthesis being carried out in an aqueous medium, optionally comprising an organic solvent and without a structuring agent, and • b) drying the gel obtained in step a) at a temperature between 10°C and 70°C, preferably between 15°C and 55°C and more preferably between 20°C and 40°C, in a gas flow in a drying chamber to obtain a monolithic nanoporous silicate sol-gel material and a residual relative humidity in the drying chamber of between 0.1 and 20%, preferably between 0.5 and 10% and more preferably about 5%.