Ah yes, the grid and flashing rim thing works nicely too...
I think the next move would be to split off the walls into a separate object and then give both those and the glass / solid panels independent thickness so that they react properly to light. That doesn't have to be done on an individual panel-by-panel basis if we remember to make sure the gridwork intersects both sides of the glass, meaning light can't bounce from panel to panel out the sides, if you see what I mean. Intersection here will be very clean, and unproblematic at these sorts of scales, unless you are planning to crawl a camera inches over the surface of them.
CBR