I want to introduce you to another solution - a door hinge valance. A door hinge valance uses hardware that allows the valance to move with the door. In this kitchen eating area, there are two windows and a door. By using door hinge hardware, the designer was able to mount all three valances at the same height AND have all three valances the same length AND still use the door without interference from the valance.
Here is an example of using door hinge hardware for a valance over a French door. Like the single door, the French door also opens into the room. This situation requires a valance design that has some sort of "break" in the middle where the valance itself hinges. The inverted box pleat in the center of this valance is the perfect solution.
Here is a third situation where a door hinge valance was used. In this case, there was a large picture window where the designer chose a valance with stationary panels. She did not want to leave the door untreated. By using the door hinge hardware and mounting the valances at the same height, your eye moves around the room uninterrupted and the customer can still use the door.
The next time you are designing valances in a room with a door, picture your customer saying "Trick or Treat". Don't be the designer that ends up with a smashed pumpkin -- like a valance that is too short. If you want to hand out full size candy bars and offer your customer a door hinge valance, email me at email@example.com and I'll help you engineer a treat for your customer.