Sheathing the roof made the skylights more visible. We know light by darkness. Within an opaque field the skylights are exclamation points of transparency and illumination.
Now I'll back up to show some process. The parapet wall facing the courtyard was built before the roof was sheathed.
Each stud for this wall attaches to a "high joist" - which is what we've been calling the upper level of joists. The lower level is for structural support of the roof, the upper level has a slope cut into each member so water will flow to an internal gutter. This gutter is open for the moment, and is the reason for the line of light running down the middle of the space in the photos below. Hm, can I get a transparent gutter?
Then the parapet wall was sheathed.
A "glass wall" will wrap the portion of the house facing the courtyard; it will sit on the center course of the brick edging seen here and extend up to the bottom of the parapet wall. Which means the beams and the ends of the joists will be visible from outside, and that light will continue to pour in between those joists just like it does now.
Once the roof sheathing was complete, I was able to visit the roof for the first time. I kinda wanted to stay.
I found this illustration of Peter receiving his vision on the rooftop (from goodsalt.com). It suggests he had a bed up there. Excellent idea.
It was also nice to see the rest of the house from the roof, especially the courtyard.
Now that the roof structure is basically complete, the next major task is roof-ING - installing the waterproofing materials: membrane, gutter liner, flashing, sealant. Now if I can just find someone good enough and crazy enough to do all that for this house.