Author laid out and cut a pattern rafter out of 2x cedar stock. The rafters will slant up at a 45° angle from the corners of the cupola and meet in the center.
Next the author traces and cuts the rest of the the rafters using the pattern rafter.
The plumb cuts on the bottom ends of the rafters receive a 45° cut in both directions to provide a nailing surface for the fascia.
To create the swooped roof, the author uses a thin batten to scribe the curve to the upper edge of each of the rafters.
The rafters attach to a plywood platform and and the tops of the rafters nail together where they meet in the center of the cupola.
For the curved roof planes, author laid out triangular pieces of sheathing with curved edges.
After installing the fascia around the perimeter of the cupola roof, author begins the roofing with drip edge along the edge of each side.