Jørn Utzon, in 1967, on the Sydney Opera House:
"[F]inally I found a solution by deriving the forms from the surface of a sphere. The photographs of the sphere model show how I can evolve the surface of the shells from the sphere and systematically construct all the roof elements. One can recognize the silhouette in the entrance shell, the shell over the stage tower and the two shells over the auditoriums – this implies that these shells harmonize with each other, they are derived from the same sphere, are sections of the same spherical surface and have the same radius. When they are spatially constructed, we thus know that they will intersect each other according to certain laws."
- Kim Dirckinck-Holmfield. Utzon and the New Tradition. Copenhagen: The Danish Architectural Press, 2005. 78
After numerous designs, Utzon came up with the universal curvature in the swells. If I hadn't known that they were all derived of the surface of a sphere, I certainly wouldn't have guessed it.
This is so elegant! (Before computers, before AutoCAD.)
My professor (who's from Sydney) was wondering what it's like to grow up in Bilbao. Very early on, we're made aware of the possibilities of architecture and design. Accustomed to witnessing built marvels or dominating styles. This is probably why every San Franciscan I know will always adore Victorian facades. It's ingrained!