Description: Coveting a desk I'd found on-line five years ago and not being able to find it in my area nor probably afford it, the following was my solution.
We bought the Hemnes desk with add-on unit plus one more add-on unit to get the height I was looking for.
Hubby built the desk per the Ikea directions until he got to the add-on unit. We flipped it upside down -- so the drawers were at the top and left the middle trim piece off of the top (which is really now the bottom). He did add the trim pieces on each of the columns and then placed a shelf over the opening -- kind of makes hidden storage that no one knows about but us!
Hubby cut down the top piece to a little wider than the add-on unit and then stacked the second add-on unit on top.
I figure I got my longed-for office space for about a third of the price.