So I've got some openings framed in FoxBuck and now I need to order Milgard aluminum windows. It will be a stucco house and I'd like the windows set back in the opening maybe 3-4 inches. So what's the best way to install them? I know I can build a wooden buck inside the FoxBuck and order a nailing flange window, but of course I'll lose 3" in height and width on the windows. I also know that old school wooden block frame windows would fit directly and I could screw through the wooden frame into the foxbuck. Neigher of those options are appealing... So my question is if I can order the Milgard Aluminum BLOCK frame windows (no nailing fin) and install them into the opening, thus I don't lose the 3"? (and I don't have to build a buck). The guy at the big box store seems to think the block frame aluminum windows are only for retrofits into existing frames, but he didn't really know. He didn't think you could screw through the frame to secure them, but that they got secured by being captured between the exterior trim and the drywall on the inside. Incidentally, we're going aluminum so they match the big aluminum storefront windows that they are adjacent to.

From my window days. You can install a aluminum tab to the window frame and screw the tab into the buck. The tab will be long enough to clear the frame. The tab allows you to install the window at any depth you want. Or replacement window style. Drill oversized hole in the frame inside the track. The hole needs to be large enough for the screw head to recess into the frame. Another hole is drilled inside this hole to allow the screw to install without binding. You just have to make sure the hole is placed where it won't interfere with the shoe that holds the sash. If you look at a replacement window at the homarama you'll get the idea. Simple.