Windows to have black frames

My inclination would be to continue to line up the vertical first and second floor but the windows i the roof could be two together or two sets of two windows together or three windows together -- get some graph paper and try symmetry or a specific look that appeals to you.

We are not moving the existing windows. Just changing the windows within those existing openings.

I would keep all the same style if a more polished look is your priority.

Keep them all double hung. Why are you considering casements for the dormer ?

Could you explain why the bottom ones need to be single and as for the rest they need to be all the same . I assume this is the first step in a larger redo of the house . Maybe take a picture from further back so we can see the whole house.

Thanks everyone. The single hung are for safety. I will do the rest as double hung.

Using muntons on the glass (not between) will improve the look substantially. The former windows should be slight smaller than the windows in the second story (but the same proportion).