You should also add a rule to lift rollershutters if you open the door, I found that to be quite useful for my shuttered doors.
There’s a lot of useful functions to implement once you have shutters.
For example, you could make them go up/down on sunrise/sunset using the Astro binding, or lower them when you turn on the TV (or at least for a ‘cinema’ scene).
For what’s it’s worth, also have a look at this full-fledged shading example.