Alfred Giles, son of Thomas and Sophie (Brown) Giles, was born at Hillingdon, Middlesex, England, on May 23, 1853. He attended the Proprietary School at Gravesend, Kent, for four years, beginning in January of 1864. A member of the Church of England, he had a boyhood ambition to enter the ministry. Upon finishing school at seventeen, Giles chose his life's work and was apprenticed to the architectural firm of Giles and Bivens in London (senior partner John Giles was not related to Alfred). As part of his training, he attended classes in the arts of construction at King's College, University of London. Upon completion of the two-year term of apprenticeship, Alfred Giles was employed by the firm for a brief period. In 1873 Giles immigrated to the United States and, for health reasons, settled in Texas. He worked for three years in the office of John H. Kampmann, a successful San Antonio contractor, from whom he acquired skill in the use of locally available building materials, especially stone. Giles established his own firm in 1876 as Reconstruction was coming to an end. Ranchers and farmers grew prosperous, and San Antonio became a focal point of commerce and amusement for a vast area. The advent of the railroad in 1877 greatly expanded the choices of building materials, and returning travelers brought with them newly awakened tastes for novelty. Indeed, the Victorian period (ca. 1840-ca. 1900) was characterized by rapid changes of style, and Giles's work reflected a great variety of styles derived from architectural forms of the past, usually in more or less new combinations. Giles's own means of expression, however, always took precedence over novelty of fashion. Giles produced designs for unpretentious domestic residences and showy mansions, county courthouses, and commercial and institutional structures all over Texas. He adapted and combined stylistic elements with restraint, sobriety, and simplicity. In San Antonio, in what is now the King William Historic District, the English architect designed residences for Edward Steves (1877) and Carl Wilhelm August Groos (1880), and on the campus of Incarnate Word College, the motherhouse of the Sisters of Charity of the Incarnate Word (1900); in Fredericksburg, the old Gillespie County Courthouse (1881); in Bandera, the old Bandera County Jail (1881); in Floresville, the Wilson County Courthouse (1884); and in Laredo, the Webb County Courthouse (1909).
As a response to decreasing commissions in Texas, Giles maintained a branch office in Monterrey, Mexico, during the first decade of the twentieth century. Buildings in Monterrey, Saltillo, Durango, Puebla, and Chihuahua attest to the firm's success. Notable extant structures in Monterrey are Banco Mercantil (1901), La Reinera (1901), and Arco de la Independencia (1910); in Chihuahua, the Palacio Municipal was constructed before 1908. Despite his far-flung enterprises, Alfred Giles served his profession well, presiding at the organizational banquet of the Society of San Antonio Architects, on August 6, 1908. He was also chosen chairman of the Texas State Association of Architects when they reorganized in 1908 in Austin. On December 15, 1881, Giles married Annie Laura James, daughter of Englishman John James, surveyor of Bexar County, Texas, and they had eight children. After 1885, with the proceeds of his inheritance, the architect began purchasing land near Comfort, Texas. His partner in land ownership was his brother-in-law, Judge John Herndon James. The ranch, named Hillingdon after the family seat in England, soon comprised 13,000 acres where horses, mules, registered Aberdeen-Angus cattle, and Angora goats grazed. Giles was a founding member of the Texas Sheep and Goat Raisers' Association and a member of the Texas Cattle Raisers' Association. Giles died at Hillingdon Ranch on August 13, 1920. He is buried beside his wife in City Cemetery Number 1 in San Antonio.