The architecture of Ottawa is most marked by the city's role as the national capital of Canada. This gives the city a number of monumental structures designed to represent the federal government and the nation. It also means that as a city dominated by government bureaucrats, much of its architecture tends to be formalistic and functional. However, the city is also marked by Romantic and Picturesque styles of architecture such as the Parliament Building's gothic revival architecture.
While the political capital, Ottawa has always been heavily influenced from the larger cities of Toronto and Montreal. This has held true in architecture, and over its history Ottawa has followed the prevailing architectural trends popular in Canada and North America. The city is thus a mix of different styles, varying considerably based on what era a building or neighbourhood was constructed in. While founded in the early nineteenth century, few buildings survive from that era and the vast majority of the city's structures date from the twentieth century. Much of the downtown was also greatly transformed in the 1960s and 1970s, and the swath of suburbs that surround the city also date from this period.
The general stereotype of Ottawa architecture is that it is staid and unambitious. Urban design consultant Trevor Boddy said that "with the relative extremes of poverty and wealth removed here, along with the vital concentrations of immigrant cultures which denote most Canadian cities, Ottawa seemed to me to represent only the hollow norm, the vacant centre.".Ottawa Citizen architecture critic Rhys Phillips has echoed these concerns, saying that Ottawa "looks like some tired little Prairie town on its last legs."
Unlike several other national capitals, such as Paris and Washington, D.C., Ottawa was never built to a master plan. However, several commissions have played a role in determining the shape of the city. Colonel By envisioned building several grand boulevards but the difficulties of expropriation and demolition prevented this from happening. In the late 1880s, Prime Minister Sir Wilfrid Laurier developed a 50-year vision of the city's future development and created the Ottawa Improvement Commission (OIC). The early years of the OIC under the direction of Montreal-born architect Frederick Todd saw the removal of industry along the canal, the definition of Patterson Creek and the transfer of Rockcliffe Park to the federal government. In 1913, Sir Robert Borden appointed the Sir Henry Holt Commission which was the first to state the need for a national capital region and also the removal of railway lines from the downtown core.