As a legal requirement we don't specify materials in anything other than mm, cm and m. In the UK the imperial measurements are sometimes also shown in a store, to help old people know what they are buying, but I've never seen that anywhere in continental Europe. Architecture isn't drawn using imperial measurements, this system is used ad hoc by UK builders only. I like to torment these luddites by specifying in mm but mostly I avoid interacting with them because I don't want to have a Mars Climate Orbiter situation at my house.