So tell me if I am missing something, frame house, single hung aluminum windows installed with the flange over the top of the 1x window trim.
The picture is awful I know sorry about that.
But I dont see any fasteners on the inside track of the window, nor any other fasteners, It looks as though its installed with adhesive!
The siding is 1 inch thick cedar plank.

any thoughts on this window installation or design?


It looks like they nailed the window fin to the face of the siding and slid the trim into the groove…not flashed at all, apparently.

Something like this nail fin and groove…

I have seen a few windows made with a nailing fin then the outer “flange” as you call it sticks out past that on the window profile. There is a gap or space between the two exactly large enough for a 3/4 inch trim / frame to be added after the window is installed. Without seeing it for myself it would be guessing. BTW, those windows I am talking about really suck at keeping out moisture because of open miter joints at the corners of the aluminum frame. The installers almost never put any rain flashing over the top of the windows so any rain or water runs down behind the top trim piece and into and around the window.

I’ve also seen the windows Doug is referring to. I have seen them installed behind the siding since the outside fin is shorter. Other than being an older aluminum window the install would be ok if it had the rain cap.

That is certainly what I thought I would find. Never ran into them down here before.
And not a spec of flashing was noted anywhere.
Thanks for the help