The main problem in the design of front systems is an empirical choice of parameters and the air gap between the cladding panels, causing appear of unventilated layer. Inadequate ventilation leads to icing of substructure elements that go into the air ventilated gap, and the top layer in winter, reduction of heat-protective properties as a whole. The aim of this work was to develop a methodology for calculating the parameters of the hydraulic flow of air in the ventilated gap, which allows determining the optimal rational dimensions of hydraulically mounted air gap in the facades of buildings and structures. As a result, it was found that, in terms of minimizing the loss there must be designed a ventilated curtain facade with ventilated air gap, expanding upwards.