The son of a Methodist minister, John Nelson Semmens was born in Toronto on June 7, 1879. He attended Wesley College in Winnipeg before moving to Philadelphia, where he graduated from the School of Architecture at the University of Pennsylvania. He married Laura Edith Carr at Portage la Prairie on June 12, 1907.
Semmens joined the eminent New York practice of McKim Mead & White, a firm specialising in the Beaux-Arts style and responsible for such notable projects as the Manhattan Municipal Building (1909–1915), New York’s Pennsylvania Station (1915) and the Minneapolis Institute of Arts (1915). In 1910 he was appointed by the firm to act as superintending architect for an assignment in Winnipeg: the design of the Bank of Montreal at the iconic corner of Portage and Main (335 Main Street, 1913). The building – a masonry Beaux-Arts structure fronted by six large columns and reminiscent of a Roman temple – would serve as a triumphant calling card for the young architect.
Following his move to what was then a booming Winnipeg, Semmens remained in the city, establishing an eponymous firm which would last until 1950. Beyond the prominent Bank of Montreal, his early work in the city included the Taylor Residence (611 Wellington Crescent, 1911-12), a three-storey red brick construction fronted by a similarly Beaux-Arts porch; and Bannatyne School (360 Wallasey Street, 1911, which with its multiple neo-classical porticoes and central red-brick block resembled the Taylor Residence. A number of other residential, corporate, academic and institutional projects occupied Semmens prior to the First World War, including the two-storey brown brick Winnipeg Public Library St. John’s Branch (500 Salter Street, 1914; the building was sponsored by the Carnegie Foundation).
With the onset of the war in Europe, Semmens enlisted in February 1913 with the Canadian Expeditionary Force as a Major with the 45th Battalion (D Company). He was avid in his interest in military affairs and served as Captain of the Winnipeg Grenadiers. Amongst other activities during the First World War he travelled to France as second-in-command with the 78th Battalion and served at such battle sites as Ypres, Somme, Vimy, Passchendaele; he was involved in the Hundred Days Offensive which concluded fighting in Europe.
Semmens resumed his busy architectural pace when he returned to Canada. A focus throughout these years was school design. Amongst others, during this era Semmens – who worked as a consulting architect for the Winnipeg Public School Board – designed: Champlain School (Machray Avenue, 1920); Florence Nightingale School (31 Shaughnessy Street, 1920); General Wolfe School (Ellice Avenue, 1920); Margaret Scott School (Arlington Street, 1920); Aberdeen School No. 3 (Stella Avenue, 1920); Wolseley School (511 Clifton Street, 1921); Sir Sam Steele School (15 Chester Street, 1921); Sir John Franklin School (Beaverbrook Street at Grosvenor Avenue, 1921); Isaac Newton Junior High School (Parr Street at Alfred Avenue, 1922); and Daniel McIntyre Collegiate (720 Alverstone Street, 1922). Many of these schools, which were largely brick, were done in historical styles, largely neo-classical (frequently with a slightly Palladian bent) or Elizabethan and often in an eclectic mix. With such great and proficient output, Semmens became known as an expert in school design and was said to have “set a standard for school work in Western Canada.” His best works from the period include Issac Newton Junior High School (1922) and Daniel McIntyre Collegiate (1922), both designed in a faithful and carefully detailed Tudor Revival style.
Beyond this realm, Semmens worked in the 1920s on residences, hospitals, warehouses, and schools in other cities and towns. He also was architect for the Salvation Army in Western Canada; assignments included a maternity ward addition to Grace Hospital (Arlington Street at Preston Avenue, 1923) and the nearby Salvation Army Cadet College (Dominion Street at Portage Avenue, 1926). Semmens was successful in the design of buildings for the growing automobile industry, amongst them: the A.C. McRae Motors Company (William Avenue, 1912); Capitol Motors (Main Street at Pritchard Avenue, 1922); an addition to the Western Canada Motor Car Company building (Edmonton Street near Portage Avenue, 1929). The 1930s Depression slowed Semmens's work significantly but government spending presented such opportunities as the Winnipeg Civic Auditorium (200 Vaughan Street, 1931-32; with Northwood and Chivers), a project whose clean lines and Art Deco detailing represented a transition toward a slightly modernist aesthetic for Semmens, whose design approach had already been moving this direction over the course of the previous decade.
From 1935 to 1939, Semmens was assisted in his work by his nephew Harold N. Semmens. The general suspension in building mostly continued during the Second World War, but early post-war years brought a renewed vibrancy, with contracts arising mainly for schools and churches. Amongst the notable works Semmens created throughout this era are the English Lutheran Church of the Redeemer (59 Academy Road, 1946); St. George’s Anglican Church, Grosvenor Avenue at Wilton Street, 1949); the United College Theological and Library Building (Portage Avenue at Balmoral Street, 1949); St. James Collegiate Institute (1900 Portage Avenue, 1950); and Sts. Vladimir & Olga Cathedral, 115 McGregor Street, 1950-51). With the exception of the latter, a lovely fusion of neo-Classical and Eastern European approaches, Semmens's architectural approach continued to evolve toward a more modernist manner in this period.
In 1925, Semmens lived at 334 Maplewood Avenue in Winnipeg’s Riverview neighbourhood. At one point his architectural office was located in the Great West Permanent Building (356 Main Street), later moving to nearby 348 Main Street. Beyond his practice, he was involved in the architectural community at a public level through his participation with the Manitoba Association of Architects; he was elected president in 1921 and again in 1941. To this day his portrait can be found at its offices. Semmens was also a member of the Kiwanis Club, the Carleton Club, and a Governor of the Elmhurst Golf Club. He retired after 1950 and moved to Victoria, British Columbia in 1957, where he died on November 4, 1960.