Josias Thomas Joesler was born in Zurich in 1895 and was raised in Arosa, Switzerland where his architect father served as mayor. His education included the study of architecture in Bern, engineering in Heidelburg and history and drawing at the Sorbonne in Paris. Between 1916 and 1923, he worked as an architect in Switzerland, Germany, Italy and lastly in Spain, from where he had traveled to North Africa.
In Barcelona, he married a Basque, Natividad Lorenzo (nicknamed Nati), and left Europe in 1924 to live briefly in Havana Cuba, then Mexico City. In 1926, Joesler moved again to Los Angeles where he nearly went broke working on his own as an architect. He was eventually hired as a draftsman at a prefabricated house manufacturer named Pacific Ready-Cut Homes. While in Los Angeles, he came to the attention of architect George Washington Smith, who referred Joesler to Murphey. The Murpheys needed an architect who could interpret their vision of elite communities and buildings that portrayed the various historical revival styles popular in other parts of the West. Joesler's extensive travels, combined with his education in both the technical and artistic realms of architecture provided the Murpheys with just the palette of styles needed to express their vision.
A year later, 1927, Murphey contacted Joesler again and convinced him to move to Arizona, where he briefly resided in Nogales before moving to Tucson. The Murphey-Keith Building Company provided Joesler with 56 jobs in 1928 alone, introducing a relationship of patron-architect that would last over 30 years. Leo B. Keith was Murphey's business partner throughout Joesler's career with Murphey, though not having much impact beyond his financial and promotional interests. Joesler did occasionally work as a sole practitioner architect, though the large majority of his work was under the patronage of John W. Murphey, together with whom he produced over 400 buildings in Tucson alone. After World War II, Joesler quit designing and moved with his family to San Diego. There, Joesler built a shopping center in Ocean Beach in which Nati opened a restaurant (which is still there). Joesler apparently got bored and moved back to Tucson in 1947, where he resumed his practice and built a few buildings before his death on February 12th, 1956.
Architects, working under Joesler, described him as a short and stocky man; frugal, but with strong opinions. He ran his office in the European tradition, with Joesler being the master and his draftsmen being the apprentices. He worked his employees hard, but also undertook the duty to teach them, as a master teaches apprentices. Joesler also had an understanding of construction and a rapport with the construction workers that other architects envied. With his ability to speak fluent Spanish to the primarily Mexican craftsmen and construction workers, they took a unique pride in his work, as exhibited in their final products. He commanded great respect from everyone who worked with him, and he valued the work that was done.