The object of research is the non-compliance of the requirements of the legislation on protection of cultural heritage objects with fire safety regulations in the reconstruction of historical industrial monuments with a change of intended use by the example of the water tower. A retrospective functional concept for the adaptation of the Hydro Tower with a laboratory building, included in the list of cultural heritage objects of the Committee for State Control, Use and Protection of Monuments of History and Culture of St. Petersburg as the "St. Petersburg Polytechnic Institute of Emperor Peter the Great", as a museum has been developed. The necessity of development of special technical specifications on fire safety in connection with the lack of requirements to ensure safety of the reconstructed buildings-monuments is shown. The system of ensuring fire safety of the historical building is presented. Method of simulation of evacuation and fire hazards establishes the necessity of applying special technical specifications on fire safety in order to ensure safe and unobstructed evacuation. Results. The practical significance of this research lies in the development of the fire safety system, including a set of volume-planning solutions and special technical conditions of fire safety as well as preliminary cost; it also assumes a possibility of application during complex estimation of the reconstruction of historical structures - water towers with adaptation for a museum in realization of the conception of the objects of cultural heritage preservation; it also promotes the analytical base accumulation for creation of normative.