While onsite measurement of air permeability provides a useful approach to assess the service life of concrete structures, the combined use of onsite and laboratory measurement of air permeability is useful to anticipate whether the target service life is to be achieved. This investigation was developed within the aim of founding the application of an air permeability test (Torrent method), based on the experimental observation of specimen geometry and surface influence on air permeability results. An experimental program was developed considering three specimen geometries, two types of surface, and twelve concrete mixes. The results were analysed and no significant influence of the tested specimens geometry and surfaces was detected. Therefore, the use of any of the surfaces or specimens geometry in mix approval or in compliance control processes is possible without correction of the results. This work constitutes a contribution to further understanding of the test method in particular and of concrete air permeability assessment in general.