Curtain Wall Exercise

For this exercise I wanted to create an curtain wall using different panels.

I started to create a panel, first modelling a frame in a curtain wall panel family and in a generic model family I created an element which I loaded to the first family and put it inside the frame. 

To have a possibility to change the dimentions of the panel I made a shared parameter for the height of the element. So now i can change the height of the whole panel but i still can't figure out how to change the width of the whole panel. I want to obtain a panel in which when I increase the width dimention the vertical elements are copied with the  constant distance between them and when I reduce the width the elements are removed, so how to make number of elements relative to dimentions of the whole panel (maybe it's a good start point for exam project?).

I loaded the family to project and created the curtain wall with the panel so for now when I make the panel spacing wider the panel has empty space between frame and elements. 

Next I created second panel with the extrusion, so here the situation is similar: I can change the width but when I choose the maximum spacing higher than the original panel, it leaves empty space between elements and when i choose the spacing lower the elements overlap.

Next I started to create the project, I chose the spacing (2500x3000). I changed the grids, separate the panel and select the panel I made before. After i chose materials for the panels. 

In the end I made the schedule for the project, sorting the panels by family and height and put the blank lines and grand totals.