In the domain of inspection of civil structures, the evaluation of permeability in the field is a major problem of durability for all engineering structures using concrete. Specifically, tightness of the enclosure vessels of nuclear plants has to be controlled regularly. The work presented here aims to estimate the capability of non-destructive techniques (permeameters, capacitive and resistive techniques) to evaluate the leakage flow of concrete structures during their service life or after mechanical, hydric and thermal damage induced by accidental loading. The methodology followed to reach this objective is based on three scales, from laboratory samples to real structures, with an intermediate step on large concrete slabs. The analysis highlights the interest of combining permeability, capacitive and resistive measurements for the evaluation of the air tightness of concrete in the field. Global measurements, performed on large slabs in steady state, and evaluation on representative specimens by Cembureau and the surface permeameter, were in accordance for most of the situations analysed in this work. From the saturation degree evaluated by permittivity and resistivity, it was possible to evaluate the apparent permeability of concrete by means of a van Genuchten law calibrated in the laboratory on representative specimens of the structural concrete.