In response to a thread concerning Door/Window Assemblies in the Autodesk Architectural Desktop 2006 Discussion Group, I posted a sample style to the Autodesk Architectural Desktop Content Discussion Group. The 2006 Discussion Group thread also contains a link to a sample style by Paul Humphrey and a sample style attached by Jeff Hanson.
The original request in the thread was for a way to have a fixed, 3'-0" wide by 7'-0" high door in the middle of a storefront frame, flanked by equal panels at a maximum width of 4'-6". In my style, I chose to set both the default frame and default mullion to the same size, 2" wide by 4 1/2" deep. The Primary Grid is assigned a vertical manual division with gridlines set at plus and minus 1'-7" from the grid middle. This sets the width of the center cell for the door. The all of the cells in the primary grid are assigned a nested grid.
The nested grid for the start and end cells of the primary grid have a vertical fixed width division with the cell dimension set to 4'-6". Auto-adjust cells is turned on and set to "Grow" - all three "specific cell" options are unselected, to generate equal widths. The default infill is used for these, which I modified to be 1/4" thick and to which I assigned a glass material.
The nested grid for the remaining cell [all unassigned] is a horizontal manual division with a grid line set at 7'-1" from the grid bottom, fixing the door height at 7'-0". The bottom cell in this grid is assigned a frameless door style, so that the door itself will fill the opening; the top cell [all unassigned] gets the default infill. A frameless door style is nothing more than a door style where the frame width has been set to 0.
After placing an instance of this Door/Window Assembly, I edited the infill of the cell with the door and turned off the bottom frame for that infill, so the door gets the full 7'-0" opening height. I transferred the Design Rules to the instance, then back to the style, saving the override to the style so that the door cell will always have the bottom frame removed. You can read a more detailed explanation of how to do that, along with how to turn off the display of sills while turning on the display of the bottom frame, to get the lines out of your door opening in plan view [which I did NOT do in the initially posted sample file] by reading a previously posted article, "Removing Unsightly Bottom Frames at Doors". Here is something that I just discovered - unachored [no wall selected when placed] Door/Window Assemblies will not automatically display the frame below, even when that component is turned on, whereas those anchored to walls will. You have to use the same trick used for Curtain Walls, and set a manual cut plane that passes through the frame on the Other tab of the Plan Display Representation [or whatever Display Representation is active for a top view direction in the Display Configuration you use for plan views]. A height of 0 works if the bottom of your bottom frame that is at that elevation.
Note that if your Door/Window Assembly overall height is not at least 7'-2", the door will be less than 7'-0" tall, since the cell will be less than that. Heights over 7'-2" and up to 7'-4" are "weird" in that the mullion gets drawn and, until you hit 7'-4", is pushed into the top frame. At 7'-4", the mullion and frame are side by side; over 7'-4" and you get some transom glass.