>but the 4cm depth is probably cutting it too close
very good. I came to the same conclusion. I thought maybe I could just use a single 20x40 or 20x60 profile for the shelves put this would make it impossible to store a lot of things in there.
Currently I'm thinking of just making the frame out of profiles and then screw some aluminum sheets on there. Then I can make them wider without impacting the cost so much and also eliminate the problem that dirt would accumulate in the slots of the profile.
>are you going to put handles on it so it's easier to slide them open?
I won't try to drill into the glass. I have some experience trying to make holes in glass and it usually ended up in shattering it. But I will probably try to glue something on there. I assume having no handles at all and tons of fingerprints all over the mirror from opening and closing it would be frustrating in the long run.
>but it all sounds very complicated
I think all I have to do is attach some U-Profile on there to form a slot and then put some low friction tape on both surfaces so they slide easily. But I have never done something like that.