While the globalization of the styles and ideas has smoothed geographical and cultural borders,the contemporaryJapanesearchitecturehasretainedaverydistinctive style.SANAAisaninternationallysigniﬁcantandprize-winningﬁrmofarchitectswhose works seem to exemplify this kind of architecture.Some of the distinctive features of their work are simplicity, transparency and formal austerity,as well as a peculiar ambiguity in the expression of materiality. What role does the materiality play in creating something uniquely Japanese out of modern architecture? Through a case-study of Louvre-Lens Museum, the paper investigates the role that materiality plays in realising the Japanese aesthetics, focusing primarily on two key material features that have been identiﬁed in SANAA’s work: transparency and whiteness. Some concepts of Japanese aesthetics are investigated in order to have a better understanding of the idea of ambiguity and weakness embedded in Japanese culture, including the concepts of mono no aware, superﬂat and philosophy of Rikyu Grey. By analysing the materiality and luminance conditions of interior space of the Louvre-Lens Museum and impact of the environment and time on exterior materiality, the paper suggests that materiality turns out to be a vital tool in the creation of a more tactile and ambiguous experience of vision, which transformed the focus of architecture from form to sensibility and perception. The Japanese aesthetic of simplicity, ambiguity and ephemerality is subtly applied through the seemingly neutral expression of materiality in SANAA’s architecture.