Please view picture of the 4 foyer windows. House built in 2003. On the inside, the water intrudes below arched window but just off to side over top of one of the lower side windows. I don’t know if the glass in top window was replace or it was a new construction window, but that did not help, and all windows were re-caulked, and that did not help. It was also re-caulked on the inside, but that did not help, and I don’t see water entering at the seems anyways. It seems to be coming through drywall.

As per an engineering report, water has infiltrated wall cavity from roof. These windows are below a gable peak, so no gutter is above, and there is no drip edge above. 

I’ve been told the water is running down fascia, and more water than usual is running down the wall behind siding, and ontop of siding since I have no d-edge. I believe the Fypon or Fypon-like window molding which due to age is wood as opposed to polyurethane is trapping the water.  There is concern about house wrap continuity. 

Plan to get new roof and drip edge. I’ve been told siding should be removed so sheathing can be inspected and repaired/replaced as needed, but not much direction regarding the window. However, I was told that would involve removing siding, and there is a need for siding and to re-wrap anyways, but redoing all 4 elevations of the house might not be economically feasible now.

Based on research, I’ve gathered I should replace windows with new construction type windows. So far, contractors in area have not used the terms construction window or replacement window, and for the most part vague and nebulous about if the window should be replaced, are all windows grouped in 1 frame or not, or if same old windows should just  be re-flashed.

A local company told me they stopped re-flashing old windows lately as they had a 90% failure rate, thus I don’t want to risk re-paying for siding just to have to have it redone. I’ve been trying to see if anyone in area is willing to do “new construction windows” on an old house, and so far my impression is they don’t like to bother doing that.

Unless I misunderstood, based on research so far, using replacement windows does not get rid of old flashing, thus even though new flashing would be placed around the replacement window since the original nail fin remains with just the replacement window adhered on top, pre-existing flashing issues from the original window can result in continued leaking, or later leaking if there was a developing leak. 

One contractor, who wants to replace the roof suggested just reflashing current window, but for all the reasons I explained – like a 90% failure by another company – I think it would be a bad idea to pay to replace all siding and house wrap and just re-flash as opposed to replace the current window, only to later have to remove siding and try to get a new window. Another company just seems to not do new construction windows on old homes. 

My questions are: 
1) Apparently window flashing tape often spans the flange/fin, some bare sheathing and house wrap, adhering to all three. Is it possible or likely the excessive water exposure has deteriorated or disrupted current flashing materials to the point the flashing is now failing, particularly if sheathing is remaining excessively wet? 

2) Could you please tell me if these 4 foyer grouped windows likely have  only one window frame and does it likely have just one nail fin/flange? Are my foyer windows possibly something other than typical new construction windows that use a different method of attaching to the house sheathing?