Why is there an X over the upper right window?

The X is a window we are replacing (some of the windows were replaced upstairs but not all so we marked all the ones that need replaced )

Paul F., I cannot tell did you make window smaller somehow ? I do not see any text just the picture ?

Why is the window on the left a sliding window when the balance are double hung? I would replace it with exactly what is there now, another DH/Pict/DH combo, same size as that is the proper proportion.

The story behind the odd windows is that we had a renter living in the house for the last 5 years , then when we sold our larger home and decided to downsize we moved back into this property. She did updates to the house in lieu of rent and only replaced a few of the windows. My husband,s office sits directly behind the house which is why we never sold the house that we bought back in 1992. Personally I don't like double hung windows, never have, probably never will. I understand they are useful on second story due to ease of cleaning but I think they are ugly and also thought if we replace with more double hung then we would have to replace the large sliding window to left of front door tomkeep the "look" even though it is a new window? The odds of me ever opening the windows is low due to the road noise but I can appreciate keeping a uniform look for sake of curb appeal. We certainly do not expect to ever sell the house for much of a profit because it is so old and located too close to the road but while we wait out retirement we plan to stay here for maybe 5-7 years then sell the entire property house and office building. hence you see why I am not just ripping every window out and starting over.

Well...reducing window opening sizes is best done when you are re-cladding the exterior...so now is your time. Once you get into an STC class of window, you won't see much offset with a smaller window. Definitely not any type of linear relationship.

With these older homes, the windows should be consistent. No casement windows if you're keeping the double-hung windows.

This arrangement could help with the noise issue.

I suspect the exterior walls of your home are overdue for improved insulation. That along with new windows will be a big benefit.

IMO all your windows should be double-hung if you are installing shakes on the exterior.

Replace all the windows so the appearance is the same. Don't cheap out on this.

Started to apply some shakes to see how the house might appear.