OTTAWA — Justin Trudeau, the leader of the Liberal Party, was sworn in as prime minister of Canada on Wednesday morning, ending nearly a decade of Conservative rule.
Mr. Trudeau and his new cabinet took the oath of office at Rideau Hall, the official residence of Governor General David Johnston. They arrived shortly after Stephen Harper, the outgoing prime minister, formally tendered his resignation.
Mr. Johnston, as Queen Elizabeth II’s representative, fulfills most of the duties of head of state here, including administering the oath of office to government ministers. The ceremonies are much more subdued affairs than the inauguration of American presidents.
Though the swearing-in took place inside Rideau Hall before a small invited audience, Mr. Trudeau broke with recent tradition by inviting the public onto the grounds of the residence, where two giant television screens allowed them to watch the proceedings.
The mood of the enthusiastic crowd on the tree-lined lawns contrasted markedly with the somber public gatherings in Ottawa on Oct. 22, on the anniversary of an attack by an Islamic extremist who killed a ceremonial guard near the Parliament building in 2014.
Mr. Trudeau is the first child of a prime minister to become head of government in Canada. But he and his family will not be moving immediately into his childhood home, the official prime minister’s residence overlooking the Ottawa River at 24 Sussex Drive.
The 34-room mansion, built in the 19th century for a lumber baron, fell into disrepair long ago. It is poorly cooled in the summer by window air-conditioners; its 50-year-old electrical wiring is strained to the limit; the plumbing is inadequate; and there is asbestos behind some walls and ceilings that needs to be abated.
A 2008 report by the Canadian auditor general called for immediate and extensive renovations, after finding that, except for the roof, the building was “in poor or critical condition.” But Mr. Harper, like several predecessors, refused to call in contractors, apparently fearing that the public would disapprove of spending millions of tax dollars on the mansion.
The work will now be undertaken, but will probably not be completed for two years. In the meantime, Mr. Trudeau and his family will live in Rideau Cottage, a building on the grounds of Rideau Hall. It also dates from the 19th century, but unlike 24 Sussex, it was recently renovated and modernized.