There are no "rules" and you may do what you wish. Unless there is some special design feature, however, the common and generally accepted approach is to have the head of doors and windows aligned to the same height above the floor.

You could align everything at 6'-8", or everything at 7'-0, or even use clearstory glazing for doors and windows and align everything at 8'-8", leaving 4" for the trim at the head of window and door clearstory glazing. Your call!

Good luck with your project!

It comes down to personal preference but if you look at classical architecture the door and window height generally don't align, and the tops of the windows will be slightly higher.

If I were working with nine foot ceilings my tendency would be to stay with a 6'8" door and go with a taller window and maybe go as high as 7'6" -8' with the top of the window. I would do a single window rather than a separate transom or clerestory.

In my old apartment building (with graduated ceiling heights), the 14 and 12 foot ceilings got 8 foot doors, but 11'6" and 10'6" window heights while the 10 foot ceilings got a 7 foot door with almost 9' foot window heights, and the 8 foot ceilings got 6'8'' doors with 7 foot ceiling heights.

A standard height door will emphasize that the ceilings are 9 and not 8, while a larger window will provide a purpose for the increased height.

I was recently in some new homes that had 9' ceilings and 8' doors and windows and thought it went very well together.

A large portion of our house has 9' ceilings and we are going with 8' doors and windows.

Design the height of the windows for maximum light and design the doors to create the desired amount of separation between rooms.

If the heads happen to be only a few inches different in height, adjust them so they are farther apart but light should rule.

Good points about natural light and the height of window heads. Generally speaking, the higher the window head, the greater the penetration of natural light into a given space.

Just don't forget to allow sufficient space above the window head for any desired trim, plus a margin of error for materials/workmanship.

Good luck on your project.

Or not have a soffit.

The height of the tops of the windows are 7' from the floor, ceilings are 9' roof pitch is 12 ( horizontal) over 10 (vertical).

For a 9 ft ceiling, a good window head height is 7-8 if the door heads are at 7-0. I would only use an 8 ft door height for wide trimmed openings and let it stand out from the lower doorways.

In a one story house a good way to add space between the exterior window head and roof eave soffit is to platform frame the attic (like a second floor) and rest the rafter or truss tails on a plate on top of the attic floor sheathing. I've never put roof framing on a top plate; don't let minor framing costs or conventional construction methods dictate the design of your house facade.