I'm advising the onwer of a 50 unit, 6 story multifamily building on how best to cost effectively control excessive heat gain in the summer. We started by looking into louvered overhang retrofits made from aluminum and attached to the 6th floor, south side units. ( The 1-5 floors have the balconies above them to shade some.) The price? $30,000 for 5 apartments. Not in anyone's price range. The existing glass is a tinted charcoal gray Insulated Glass Unit. For that reason, window film installers are saying that they can't guarantee the glass won't break if they install. I'm not even sure myself that insulated window quilts or a product like Comfortrack Plus by Comfortex would not cause breakage to a dark tinted glass IGU since tinted glass absorbs heat rather than reflect it. Any ideas on the best solution?