With tilt and turn windows I can only think of two options, either face mounted shutters to the actual window, which the fabricator might offer, or a rod hung on the face of wall above the window opening, to avoid the window catching on them. A track sheer or drape will work aesthetically, but practically?? Presuming when the windows open, so too would the curtain, it only matters at the end of day when you want to close up and have privacy, so perhaps a holland blind (pull down) so it's least conspicuous.
mldesign0401
Kevin Anders