The frame is of Cypress. Bone soaking wet, and big. Most timbers are either 8"x 12" or 12"X 12". Totally oversized and guaranteed to shrink and move. The room is (drum roll please), 30 feetx 80feet, two large dormers intersecting the frame in the center. One dormer creates a gable end, the other is a large bump-out porch (this one is filled in by conventional framing, then you walk into the porch). Where I mentioned rabbetting before, and "letting in", we're also applying a compressible(and later, expandable) gasket to help seal the perimeter's of the glazing. Fixed glass will be measured to each opening independently.
joel