Antoni Gaudí was one of the most famous Spanish architects. Gaudí was known as one of the most unique architects in the early 20th century.
He introduced new techniques in the treatment of materials, such as trencadís which used waste ceramic pieces, making an early green statement.
(Casa Batllo designed by Gaudí)
The Spanish Colonial Revival Style: Spanish Colonial Revival Style is found most frequently in warmer regions of the United States such as California, Florida, Arizona, and Hawai'i. In California the style was initiated by Bertram Goodhue and Carleton Winslow, becoming a dominant regional style.
Architect Lilian Jeannette Rice designed the style in the development of the town of Rancho Santa Fe in San Diego County in early 1920's. The city of Santa Barbara adopted the style to give it a unified Spanish character in 1925. The County Courthouse, designed by William Mooser III, is a first class example.
(Santa Barbara County Courthouse, designed by William Mooser III) https://en.wikipedia.org/wiki/File:Santa_Barbara_County_Courthouse2.jpg
The Pasadena City Hall by John Bakewell, Jr. and Arthur Brown, Jr. , the Sonoma City Hall, and the Beverly Hills City Hall by Harry G. Koerner and William J. Gage are other notable civic examples in California. Between 1920's and early 1930's, architect Robert H. Spurgeon built 32 Spanish colonial revival houses in Riverside and many of them have been preserved.
The city of San Clemente "The Spanish village by the sea", founder Ole Hanson opted towards Spanish Colonial Revival style in his founding and development of the city in 1928. Hanson had a clause added to the deeds requiring all building plans to be submitted to an architectural review board in an effort to ensure future development would retain red tile roofs and white exteriors, Spanish colonial architecture style mainly characteristics.
Spanish Colonial Architecture style is mostly identified by; red tile roofs, flat roof space, exterior and interior round arches, wooden look window frames and doors, stucco walls, now combined with large glass doors and big windows.