WB Marta, First a clarification - 5/16 and 7/16 refer to laminated glass which is two lites bonded either side of a plastic interlayer, those thicknesses are not the actual thickness of individual glass lites. 5/16" laminated glass consists of two 1/8" lites and 7/16" laminated has two 3/16" lites so that the 1/8" difference is really 1/16" x 2. Different glass thickness does not mean different frame thickness, it doesn't even affect the width of the reglet or glazing channel in the sash. Because the vast majority of glass that goes into the sash is going to be a dual pane package that will be the same width (or depth depending who you are talking to), even when different glass thicknesses are used by changing the width of the spacer between the two lites, the overall IG width doesn't change. In other words, if window company xyz has an overall glazing channel of 1" for their dual pane units, then that's what the IG unit has to fill. Depending on the window company the tolerance for the IGU width might be as little as 1/64". Available options might be two 1/8" lites with 3/4" space between, or could be one 1/18" plus one 1/4" with a 5/8" width spacer/airspace. Or if they were manufacturing an impact window with 5/16" laminated and 1/8" mono glass then they would use a 9/16" spacer to once again come out at 1", and so on. In your case Marta, you are being told 5/16 and 7/16 but are they selling a single laminated lite in a frame or are they going to be IG (dual pane) units? Either option is available in Florida, but IG is more common. This part is a bit more complicated..... The advantage of thicker laminated glass in an impact window has to do with wind resistance and potentially the DP rating. Simply thicker glass generally has higher load tolerance (wind and otherwise) than thinner glass, but thinner glass that has been heat strengthened or tempered has a higher wind loading tolerance than does non-heat treated (annealed) glass even when the annealed glass is thicker than the heat treated glass. Need to raise the DP of a given window? Temper the glass and it immediately goes up. What all that means is that if the 1/8" glass in the 5/16" laminated has been heat treated and the 3/16" glass in the 7/16" has not, then the thinner 5/16" heat treated laminated glass has substantially higher resistance to wind pressure and low level impacts than the non-heat treated 7/16" laminated product. However note low level impact resistance. There is no appreciable difference between 5/16 and 71/6 laminated glass when subjected to the 2x4 hurricane impact test requirement. Heat treating glass might protect from an errant baseball but the 2x4 doesn't even notice the difference, heat treated or not. The downside to heat treating is that it can introduce distortion in the glass, distortion that may even be unnoticeable in a single lite of glass can become quite noticeable when two lites are laminated together. I am not saying it WILL be distorted, far from it, just saying that the possibility is potentially greater. And most (but not all) distortion when it does occur is very mild and only visible at acute angles to the glass, often even affected by lighting conditions to see it. Marta as you move forward the first things that you need to find out are, a) monolithic lami or IG unit in the windows b) is the glass heat treated, either heat strengthened or tempered c) if an IG or dual pane, is the non-laminated (also called sacrificial) lite heat treated d) if monolithic lami what LowE coatings, if any, are used in the construction And all else being equal, monolithic can be okay and IG can be okay. Depending on location and application eat treated can be a good option, but non-heat treated might be just as effective. Coatings are a necessity, mono or IG, that one isn't negotiable.

QUICK energy saver if you have a flat surround on the windows. Use cheap curtain rods, the compression kind, and make a quick "cafe curtain" of sunshade fabric. The one shown has been up for 1.5 summers in NM and still doing well. I just stapled the fabric to make a "hem" for the rods to go through. They - thanks to physics - do NOT blow off in a high wind.

Disagree with above comments. Impact windows add a lot of value to homes in SW florida for resale purposes. But you want to make sure you replace all of them -- not just some -- so that buyers can be assured that they will get the insurance discount. We were in a house in coral gables in the italian historic village (near CG high -- i'm assuming near your house), and without impact windows, our hurricane insurance was $17,000 a year. It went down to $10,000 with all impact windows. This is a question that EVERYONE asks about when you go to sell your house. Impact windows and date of roof. It's HUGE for resale purposes. I'd also argue that houses in historic areas in Coral gables and the grove are actually considered more aesthetically pleasing *with* the impact windows. It's considered a marker of a house that has been fully renovated. This is different than, say, washington DC (where i also lived) where aluminum new windows from the 90s are considered the sign of a cheaply done flip 20 years ago. Conversely, the thick border that is a give away of impact windows in florida is a sign of a good renovation. I have never heard of anyone in SW florida being particularly concerned with maintaining the historic elements of the old houses. They like the appearance of the old houses, but want the updates of new houses. This is also different than DC, where people tried to maintain the old features.

@overhear Before the last two summers' restoration work, many of the sashes were painted shut, and a lot of the aluminum storms didn't open more than 20 cm (8"), so we have a lot more air movement in the house now. Most of the summer, we're able to keep the house cool by closing everything up during the day, and then opening windows and putting window fans in the bedrooms at night. Considering that the house has no insulation in the walls, this is no small feat! I was initially concerned about whether enough breeze would get in because of the way the casements open, but it wasn't an issue last summer. As for maintenance - the house is covered in original, 140-year-old wood trim, including a lot of "gingerbread" that I've been stripping and restoring over the last two years. The old growth wood is in amazing condition, (other than a few areas with rot that I repaired with Rhino wood repair - an amazing product!) In general, new growth wood doesn't last nearly as long, but when primed and painted, new wood windows will last longer than vinyl replacement windows, which are rarely guaranteed for more than 10 years. Mine are made of accoya, which is a specially treated wood product that is supposed to last up to 50 years! I'm estimating that touch-ups to paint will be necessary every 5 years or so, but the trick is to keep up with touch-ups so that a major repainting isn't necessary. Putty should be replaced every 20 years (mine have gone too long!) but my storms have wood stops so they won't need to be redone. This website has a lot of good information about wood windows: https://www.oldhouseguy.com/windows/