Last summer a customer asked me to design and build a Victorian- style cupola for a renovation project. The features he wanted included round-top shutters, a curved hip roof coming to a peak, and a means of fastening a weathervane at the peak. The base of the cupola was framed, sheathed, and trimmed in conventional fashion, but rather than build custom round-top shutters, we agreed to use stock rectangular shutters and overlay the curved trim. The real challenge lay in framing the roof . We experimented with full-scale mock-ups to find the appropriate size and bend of the rafters. The common rafters are arcs of a circle with a 7-foot radius. The hip rafters are a bit trickier because they are elliptical.