The impact of shading devices on the airflow across large openings during single-sided natural ventilation is investigated through an extensive experimental campaign. To quantify this impact the approach of the correction coefficient, already applied in non-shaded openings is used. The proposed methodology is independent from the climatic conditions of the test site. The correction coefficient and the corresponding Archimedes number are determined experimentally. The regression equations to determine the correction coefficient as a function of the Archimedes number are determined using a regression technique that takes into account the errors in both axes. The combined standard uncertainties of the parameters of these equations are estimated according to the widely accepted guidelines of the International Standardization Organization. The methodology followed is presented in detail. The proposed equations improve the accuracy of network models in buildings thermal simulations.