Information from Wikipedia

Arthur Rolland Kelly (July 4, 1878 – March 25, 1959) was an American architect who specialized in residential architecture, primarily in the Los Angeles, California area. Arthur Kelly designed approximately five hundred homes and other buildings.

Among his first jobs was working for the architectural firm of Greene and Greene in Pasadena. Within a few years, he opened his own architectural firm, initially creating homes in various styles in Hollywood and surrounding areas. In the book California Design 1910 author Robert Winter states "The majority of his residential work during the Craftsman period leans toward Colonial Revival and is of only marginal interest. Winter goes on to note one exception, the ca. 1909 John T. Allen ranch house, Hollywood.

The 1920s saw a very prolific period in Kelly's career. His specialization was in homes of Spanish Colonial Revival style and Tudor Revival style. Most of his clients chose to have his designs built on lots they had purchased in Holmby Hills, Beverly Hills and San Marino, California. Kelly's associate during this period was Joe Estep. A few of Kelly's many designs included the William S. Hart Ranch in Newhall, the Arthur Letts, Jr. estate in Holmby Hills (now known as The Playboy Mansion), Beverly Hills estates for J. Crampton Anderson, John Blystone, Richard Dix, Johnny Mack Brown, and many others. During this period, Kelly also designed all the buildings for the Westlake School for Girls (now known as Harvard-Westlake School) in Bel-Air and the Wilshire Country Club in Hancock Park.