William Gray Young was the son of Matthew Gray Young and his wife, Agnes Anderson Barclay, and was born in Oamaru on 21 June 1885. His father had arrived in New Zealand from Scotland as a watchmaker, and developed skills as a jewellery retailer in partnership with his brother. They moved their business to Wellington in the 1890s.
William was educated at the Terrace School and subsequently at Wellington College. He was observant, and critical of his environment and instruction; his scholastic ability and innovativeness were early recognised and rewarded. On leaving school he was articled to the architects Crichton and McKay. He became a valuable associate, studying at the evening classes of the Wellington Technical School and becoming trusted with design, documentation and supervision of commissions. The Wellington Boys' Institute building in Tasman Street was one such building. In 1906 he won £150 as first prize in the design competition for Knox College, Dunedin.
In 1907 Gray Young (as he became known) was made an associate of the New Zealand Institute of Architects (NZIA). That year he went into practice on his own and from 1914 had a succession of partners. In 1913 he was elected a fellow of the NZIA, probably the youngest man to be so honoured. On 16 September that year he married Irene Deans Webster at Wellington. They were to have three daughters and one son.
In 1905 Gray Young had been well placed in a competition for working-men's cottages in Petone, and four were built to his designs. These were an interpretation in timber of the English Vernacular style. He was greatly influenced at that time by the work of C. F. A. Voysey and Sir Edwin Lutyens, while John Ruskin's influence ensured that his early work was without unnecessary detail or ornamentation.
The increasing influence of Lutyens, coupled with an abiding regard for the work of Christopher Wren, led Gray Young, even by 1913, to dabble successfully in the neo-Georgian style. A classic example of his work in that genre is 43 Kent Terrace, Wellington, an excellent brick two-floored building, now the headquarters of the Royal Australasian College of Surgeons. The neo-Georgian house of 1930 on the Pitt Street–Wadestown Road corner and his vast Lutyenesque Longwood homestead for the Riddiford family in Wairarapa are also fine examples of his work. The internal decoration, particularly the plasterwork at Longwood, was in a class of its own.
Gray Young and his partners designed and oversaw the construction of an average of six houses a year between 1907 and 1962; the peak was 1912, with 16 houses under construction. In his later years he ventured tentatively into the international style, incorporating rectilinear forms without ornamentation. His design of the 4 Murrayfield Drive house in Thorndon is a first-class example.
Gray Young worked in collaboration with Stanley Fearn and Austin Quick just prior to the First World War. He and his partners volunteered for military service, but he was judged unfit. He continued his mainly residential practice until Fearn rejoined him in 1919. Each went his separate way after two years. In 1919, with John Swan, Gray Young designed the Wellington Technical College. His best-known works thereafter were the Christopher Wren-influenced Scots College (opened in 1919); the gold medal-winning Wellesley Club (1925), which is regarded as a masterpiece in Georgian precision; the residential hostel Weir House, again much influenced by Wren; and the new Wellington railway station (designed in 1930 and opened in 1937). This is a powerful building and a very successful exercise in neo-classicism. In 1936 Gray Young was one of the architects invited to work with the government architect in the design of the prototype state houses. His contribution was responsible for their high standard of design.
Gray Young's 1945 railway goods offices in Waterloo Quay were perhaps his most successful venture into the international style. The building is vastly better than his later ones, such as the Easterfield building at Victoria University College (1951) and (with Ian Calder) the YWCA building in Willis Street (1956). The Christchurch railway station, conceived in 1940, was not built until 20 years later and showed the influence of Dutch modern architecture. Gray Young had visited Holland on his second overseas trip in 1951, having travelled to Europe earlier in 1927.
Although he was a council member of the NZIA for 20 years, NZIA president (1935–37) and president of the Rotary Club of Wellington (1935–36), Gray Young was not a public person, preferring the company of professional colleagues and a group of yachting friends. He was held in some awe by contractors and sub-contractors because of his demanding standards and on-site inspections, and his partners and staff well knew he was intolerant of fools.
Although perhaps lacking originality, Gray Young was one of the most significant architects of his era. The Vernacular, neo-Georgian and neo-classic buildings of his early and middle years are remarkable in themselves and in many cases contribute massively to their environment. His houses, often unique in form and plan, are increasingly treasured. Gray Young died at Wellington on 21 April 1962. His funeral was held in the Wellington crematorium, one of his last commissions. He was survived by his wife and children.