Mid-century Catalan architect
The veil has been lifted, and the author has been revealed as Barcelona-born architect José Antonio Coderch (1913–1984), one of the most prominent post-war architects working in Spain.
Link: MEAM Net - José Antonio Coderch
Photos: El Poder de la Palabra
Photos: Casas - Escuela Técnica Superior de Arquitectura de Granada - Casa Ugalde
Photos: Casas - Escuela Técnica Superior de Arquitectura de Granada - Casa Rozes
Book: William Stout Books - Jose Antonio Coderch Houses
Reference: Name that modernist! (Land+Living)
Oh, and by the way... I didn't win with my shot-in-the-dark guess of Mexican architect Juan O'Gorman. But at least I didn't think it was Wright, Barragán, Neutra or Siza like many others apparently did. I wouldn't say that any of those architects qualify as "lesser-known" with the exception of Wright... but what do I know.

Casa Ugalde, 1951 - Caldes d'Estrac, España

Escuela de Arquitectura, 1978 - Barcelona, España


...and the winner is...