On space efficiency: Looking through the online listings for literally thousands of Paris apartments, one thing that stands out is that they really use the heck out of what they call "mezzanines" and I guess we in the US would call raised sleeping platforms. The bed is a mattress, pillows & bedding 6 1/2' or 7' off the floor, with ladder access (rarely, built-in steps), leaving the area below it available for couch, table/chairs, shelving, etc. I like it - though at my age, I'm not convinced having to climb up and down a ladder to get into and out of bed is such a great idea. But space-saving, yes! Maybe use that platform for (tidy and decorative) storage...?