Well, it may be a small annoyance, or a big one if you are a perfectionist!
Read on to see how to hack and save space. It will require a hand saw for metal, and a router.
Step 1: Using the IKEA Online Planner
After opting for doors, when placing the drawers, you may notice some unexpected spaces (marked "?!?" below), but the images are pretty small and faded, so you'll miss them easily.
The wasted space seems meaningless, but believe me, in practice, you'll notice it. The bad thing is that you cannot use that space at all.
Step 2: Why these Damn Extra Spaces?
The answer is: the door hinges are on the way!
Step 3: The Solution
- make a cut into the bottom-most slide
- make a groove into the fourth drawer
Step 4: Bottom-Most Drawer
Then, mount all four slide pairs, and place the three bottom-most drawers.
Gain: one space.
(There are still two spaces wasted at the very bottom.) But hold on, the best is yet to come.
Step 5: Fourth Drawer
A router is a strange and dangerous power tool. Use a lot of caution and train on a piece of scrap wood! Wear protective glasses. Work slowly. Unplug the cord whenever tuning the tool.
Don't meet the screws: let at least 2mm of the thickness remain. The groove is quite wide, so make it in 3 passes, the center pass first.
Then place this drawer.
Gain: 5 spaces (almost the height of one drawer!)