A new approach for estimating the structural parameters of asymmetric porous skin layer membranes fabricated by Loeb-Sourirajan method, to overcome the limitation of the models which are in existence is focused. Agreement between the calculated and the experimental data was then examined for all models to show the superiority of the newly proposed model. In particular, the new model could resolve the imperfections of the presently available models possessing the following superiorities: (i) scanning the entire range of permeance versus pressure diagram, (ii) no limit due to the conditions of data collection, and (iii) in contrast to the presently available models, the proposed model is capable to obtain the surface porosity (S) and the skin thickness (lp) separately. Interestingly, a high correlation was observed between the results of the wet/dry flow test and the proposed approach. The proposed model also makes it possible to correlate the structural parameters of the membrane with the condition of membrane fabrication. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.