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MacKay Castle

1 Sussex Drive, Ottawa, Ontario, Canada

Formally Recognized: 1986/10/03

General view of the MacKay Castle front façade, 2003.; Agence Parcs Canada / Parks Canada Agency, 2003.
Front façade
Aerial view of the MacKay Castle, 1977.; Government House/ Résidence du Gouverneur général, 1977.
Aerial view
No Image

Other Name(s)


Links and documents

Construction Date(s)


Listed on the Canadian Register: 2008/04/02

Statement of Significance

Description of Historic Place

Constructed over many periods, to the visitor MacKay Castle presents a grand pedimented formal façade that incorporates extensions added by former Governors General. Reached from the main gates by a winding roadway, MacKay Castle is the centrepiece of an extensive property, Rideau Hall, laid out in the manner of a 19th-century country estate. The designation is confined to the footprint of the building.

Heritage Value

MacKay Castle was designated a Classified Federal Heritage Building because of its important historical associations, because it establishes the character of the neighbourhood, and because of its high landmark value. The designation applies to all remnants of the original house built by Thomas MacKay and to those subsequent additions and alterations, which contribute strongly to the present grandiose, if eclectic, nature of the complex. As the official Government House, the residence of the Crown's representative in Canada, the MacKay Castle at Rideau Hall it is a focal point of political and social life in the nation's capital.

A two-storey wing was added in 1865, the ballroom in 1873, the tent room in 1876-78 and the Minto wing in 1898-99. In 1914 a grand pedimented front was built to link the ballroom to the tent room creating the characteristic view of MacKay Castle at Rideau Hall familiar to most Canadians today.

Sources: Staff Report, Rideau Hall, Ottawa, Ontario, Federal Heritage Building Review Office Building Report 85-066; Rideau Hall, Ottawa, Ontario, Heritage Character Statement, 85-066.

Character-Defining Elements

The heritage value of the MacKay Castle is reflected in:
- its evolutionary character, which records the tastes and ambitions of a succession of notable occupants;
- the landmark northwest façade, the ballroom, the tent room, the south façade of the long 1865 addition, and the greenhouse;
- the relationship of the building to its grounds, which have their own intrinsic value.




Recognition Authority

Government of Canada

Recognition Statute

Treasury Board Heritage Buildings Policy

Recognition Type

Classified Federal Heritage Building

Recognition Date


Historical Information

Significant Date(s)


Theme - Category and Type

Function - Category and Type




Single Dwelling

Architect / Designer



Thomas MacKay

Additional Information

Location of Supporting Documentation

National Historic Sites Directorate, Documentation Centre, 5th Floor, Room 89, 25 Eddy Street, Gatineau, Québec

Cross-Reference to Collection

Fed/Prov/Terr Identifier




Related Places

General view

Rideau Hall and Landscaped Grounds National Historic Site of Canada

Rideau Hall and Landscaped Grounds is a large wooded estate located near the Ottawa River in the nation’s capital. Since 1864 it has served as the residence of the Governor…


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