A window seat (or a vintage trunk) can stand in for a file cabinet when fitted with freestanding hanging-file-folder racks, available in various widths to suit any size storage space. - would be great with built in desk on either side!
8 Space-Saving Organization Ideas for When You Don't Have a Walk-in Closet
Storage Bins-less expensive than drawers Keep your closet clutter free with a couple of canvas storage bins. They are great for storing socks, scarves and out-of-season clothing. And the best part is they are easily accessible and just as easy to clean.