The easiest way to make louvres on/in curtain panels is to do the following:
Make a mullion profile of the shape and offset desired. Load into project.
Make a (louvre) curtain wall type which includes above mentioned mullion profile and desired spacing.
Using the TAB key Insert louvre curtain wall type in place of panel at desired locations.
Credit to Daniel Friesen from the AUGI forum.
I would like to add one more thing to this...
If you would like to have a single panel of glass behind the louvres you may need to do this:
Make a curtain wall with the conventional mullions and glass panels.
Make a curtain wall that only contains a modified mullion that acts as a louvre. Its panel will be the empty panel type.
Draw this curtain wall in front of panels that need louvres. You may lock/constrain it to the backing curtain wall.