Rooflights - Design Simulation

Hello,

I'm running some frequency simulations for areas that contain rooflights. I've been asked to advise on how many rooflights should be openable, and by how much, to maintain a comfortable temperature in the space.

What does the software mean by 'fraction of rooflight can be opened'?

For example, I assume a top hung rooflight on a roof with a 10 degree pitch, that only opens 20 degrees would be input as '1'.

AND

A rooflight on a horizontal pivot on the same roof would also be input as '1'?

In reality the horizontal pivot rooflight would provide a greater window opening area than the top hung one, but the software would treat the rooflights exactly the same.

Is my interpretation correct?

Kind Regards

Andrew