Well, I had the opportunity to come across several meters of 21 x 21 mm rods of pinewood. What would you do with such a pile of long thin wooden kind ofnon-cooked giant-sized spagetti, if not shelves for the entrance hall?

A lot of sawing, and a lot of sanding and glueing, and a little drilling and som pegs was all that  was to it. No nails, no screws used.

Dye staining (water soluble, applied with a brush) in the three colors of dark oak, brandy and dark gren makes it look like it has been standing in the forest for twenty years or so...  

A very boring radiator is now hidden behind the shelves.

Very simple, and very easy to make.