Rideau Hall is, since 1867, the official residence in Ottawa of both the Canadian monarch and his or her representative, the Governor General of Canada. It stands in Canada's capital on a 0.36 km2 (88 acre) estate at 1 Sussex Drive, with the main building consisting of approximately 175 rooms across 9,500 m2 (102,000 sq ft), and 27 outbuildings around the grounds. Rideau Hall's site lies outside the centre of Ottawa, giving it the character of a private home.
Most of Rideau Hall is used for state affairs, only 500 m2 (5,400 sq ft) of its area being dedicated to private living quarters, while additional areas serve as the offices of the Canadian Heraldic Authority and the principal workplace of the governor general and his or her staff; either the term Rideau Hall, as a metonym, or the formal idiom Government House is employed to refer to this bureaucratic branch. Officially received at the palace are foreign heads of state, both incoming and outgoing ambassadors and high commissioners to Canada, and Canadian Crown ministers for audiences with either the viceroy or the sovereign, should the latter be in residence. Rideau Hall is likewise the location of many Canadian award presentations and investitures, where prime ministers and other members of the federal Cabinet are sworn in, and where federal writs of election are dropped, among other ceremonial and constitutional functions.
Rideau Hall and the surrounding grounds were designated as a National Historic Site of Canada in 1977. The house is open to the public for guided tours throughout the year; approximately 200,000 visitors tour Rideau Hall annually.