The Association “Roselectromontazh” conducted a study of electrical loads for residential and public buildings in the Republic of Tatarstan showed that actual electrical loads are 1.5 - 2.5 times lower than in regulatory documents. Recently constructed cable networks and transformer substations of 0.4 / 10 kV in fact turn out to be underloaded. Moreover, this underload is such that most of the transformers rarely operate at 30% of their capacity during hours of maximum power consumption. The calculation of electric load is the basis for designing the power supply system of any capital construction facility. According to the open joint-stock company “Network Company” and with the support of the President of the Republic of Tatarstan, the Association “Roselectromontazh” carried out an experimental study on updating the requirements for calculating electricity consumption in public and public buildings of the Republic of Tatarstan. The actualization of electrical loads will lead to a significant economic effect by reducing the declared capacity and accordingly the power and number of power transformers reducing the cross-sections of power cables and consequently, capital costs during construction and operation.