Home is 13 years old.
Original installation of Anderson Narrowline double hung windows.
Siding is hardcoat stucco over R-Max foamboard sheathing.
The trim around the window (vinyl clad wood frame) overlaps the frame and sill of the window at the exterior. There is an open seam along the sill where water from the sill runoff is diverted into the trim and behind the stucco. The wood within the vinyl cladding is decaying from water intrusion. There is no flashing present behind the trim and/or at the sill/stucco intersection.
I have not seen this trim detail before. It appears to be a poor design detail to intentionally have the water from the sill to be divertedbehind the trim. Any thoughts or encounters with this install?