Hi GBA, My name is Ezra and this is the first time asking a question here. I’m looking to finish my attic in my small colonial built in 1919. The attic is currently open and uninsulated with loose insulation in the floor, but i plan on installing 4 inch rigid foam in the 2×6 rafters, giving me r25.5 (i live in buffalo, ny). I wanted to ideally not have a flat ceiling, but a knee wall on one side. The roof currently has no ridge vent or soffit vents, just 8 roof vents in every other rafter near the ridge and 2 gable windows as well as four windows in the front facing dormer. My question is: If i install soffit vents in the eve can I insulate and dry wall up to the ridge? Will the 1.5″ gap between the foam and the roof be enough ventilation to the roof vents? If yes, do I have to line the soffit vents up in the same rafter as the roof vents, even though air pocket of the eve is open space? Thanks