1. In a chlorosilanes hydrolysis method comprising hydrolyzing chlorosilane in a stoichiometric excess of water to produce a polysiloxane hydrolyzate and an aqueous hydrogen chloride solution, whereby hydrogen chloride is recycled by heating the resulting aqueous hydrogen chloride solution obtained from the hydrolysis to form a constant boiling HCl-water azeotrope and anhydrous hydrogen chloride requiring a major amount of input energy, the improvement which comprises hydrolyzing the chlorosilane in substantially a stoichiometric equivalence of water to produce substantially the same polysiloxane hydrolyzate as obtained with excess water, anhydrous hydrogen chloride and a saturated aqueous solution of hydrogen chloride, whereby the requirement of a major amount of input energy is avoided.