Void Shield Generator Ideas

I am looking at adding one of these to my army now am thinking of ideas on how to construct one.

What we know is that is an impassable building with battlements - I think the closest thing would be the weapons section of the FoD or one of the new weapons batteries.

I'd like to know what you think the size of it would be and how you'd go about making one.

I am thinking roughly 4x4x3 (LWH) then battlements... As for the aesthetic...not sure yet!