If you want to quickly check an opening height and also show the opening width, you can do this with a simple check box in the Dimension Type Properties.

These dimensions work with Door and Window Families. The resulting dimension will display the opening height underneath the opening width dimension.

Now you can display the opening height throughout a plan view on all openings.

You shouldn’t use this in our final dimensions on the documentation as it isn’t a standard way of representing an opening dimension.