Before we discuss the minimum Drawer Front height, lets also touch on drawer opening height while we are on the subject. The actual question we get is "why can't I make my drawer opening height less than 132mm (5-3/16")?"
Talking about opening heights in relation to Full Access is just not relevant since pretty much every dimension needs to be calculated off of cabinet size less reveal. The mindset needs to shift from opening sizes and overlays to cabinet sizes and reveals, so let's talk about desired drawer front height instead of drawer opening height.
Also, by default, we offset the mid-rail under the top drawer, which can make a discussion about opening heights even more confusing, so to touch on that topic, here is a quick overview (there is another item in this FAQ list that covers this topic in more depth).
We offset (push the mid-rail down) so all but the reveal (typically 3mm or 1/8") is available for doors below to land on, making the bumper pad position on the doors below less critical.
This offset looks something like this (the left image is with line 69 of the Shop Standards set to 8mm, the right image is with line 69 of the Shop Standards set to 0mm):
If you prefer this mid-rail be centered as shown in the image to the right, then simply set line 69 of the Shop Standards to 0mm (0"), and it will stay that way until you change it (KCD updates will not affect settings you change).
Changing this mid-rail offset will affect the size of your drawer opening, so be aware of that before you start attempting to get your desired drawer front height.
To answer the question about minimum Drawer Front height, we have to visit our Drawer Box heights since they influence our minimum Drawer Front height, and Drawer Box height (the exterior height of the drawer box from bottom to top) will be determined by the Drawer Front height, and are as follows:
For drawer front heights from 117mm (4-5/8") to 147mm (5-49/64"), the drawer box will be 64mm (2-1/2") tall (height).
For drawer front heights from 148mm (5-13/16") to 180mm (7-7/64"), the drawer box will be 102mm (4") tall (height).
For drawer front heights from 181mm (7-1/8") to 205mm (8-5/64"), the drawer box will be 127mm (5") tall (height).
For drawer front heights from 206mm (8-3/32") to 256mm (10-5/64"), the drawer box will be 152mm (6") tall (height).
For drawer front heights from 257mm (10-3/32") to 309mm (12-5/32"), the drawer box will be 203mm (8") tall (height).
For drawer front heights from 310mm (12-11/64") to 358mm (14-3/32"), the drawer box will be 254mm (10") tall (height).
For drawer front heights from 359mm (14-7/64") and taller, the drawer box will be 305mm (12") tall (height).
As you can see from the list above, a Drawer Front height of 147mm or less will result in a drawer box height of 64mm (2-1/2"), which would be a big mess for most cabinetmakers if we allowed you to make a Drawer Front that would provide you with 64mm (2-1/2") drawer boxes.
So, to prevent that from happening, we do not allow you to make your Drawer Fronts any less than 148mm (5-13/16"), which with our default 8mm mid-rail offset would provide you with a 132mm (5-3/16") irrelevant opening height. And a 148mm (5-13/16") Drawer Front with the mid-rail offset set to 0mm will provide you with a 124mm (4-7/8") irrelevant opening height.
The one exception is the Knee Space Drawer units, they will allow you to make a Drawer Front height that will allow use of our 64mm (2-1/2") drawer box.