Centre Block

The Centre Block (French: Édifice du Centre) is the main building of the Canadian parliamentary complex on Parliament Hill, in Ottawa, Ontario, containing the House of Commons and Senate chambers, as well as the offices of a number of members of parliament, senators, and senior administration for both legislative houses. It is also the location of several ceremonial spaces, such as the Hall of Honour, the Memorial Chamber, and Confederation Hall.

Built in the Gothic Revival style, the present Centre Block is the building's second iteration. The first was destroyed by fire in 1916; all that remains of the original building is the Library of Parliament, at the rear of the Centre Block. Though construction began immediately after the blaze, sculpting work on the interior continued through the 1970s. Then, from 2018, MPs were moved elsewhere for renovations lasting until 2031.

One of the most recognizable buildings in Canada, the Centre Block is depicted on the Canadian $10 bill (the Library of Parliament), $20 bill (the Peace Tower), and the $50 bill.

Designed by Jean-Omer Marchand [fr] and John A. Pearson, the Centre Block is a symmetrical structure, 144 m (472 ft) long by 75 m (246 ft) deep, and six storeys high,^{[full citation needed]} built in the modern Gothic Revival style. As such, it displays a multitude of stone carvings, including gargoyles, grotesques, and friezes, keeping with the Victorian High Gothic style of the rest of the parliamentary complex. The walls are faced with more than 50,000 blocks of over 24 different types of stone, though a rustic finished Nepean sandstone is the predominant kind of masonry, with dressed stone trim around the 550 windows and other edges. The roof is of reinforced concrete covered with copper, and dotted with dormer windows. The interior walls are sheeted with Tyndall stone, a dolomitic limestone quarried in southeastern Manitoba and chosen by the architect for the richness of its vibrant colour and rich pattern formed by darker brown spots which are fossilized shallow marine mud burrows. These surfaces are augmented by sculptural decoration done in Indiana limestone.

The Centre Block houses offices and facilities, including the office of the Prime Minister, that of the Leader of the Official Opposition, and the offices of other party leaders, as well as senators, ministers, and Commons staff. Further, there are numerous parliamentary committee rooms and the Parliamentary Press Gallery.

The Centre Block is arranged symmetrically around Confederation Hall, located immediately inside the main entrance. It is an octagonal chamber, the perimeter of which is divided by limestone clustered columns into eight bays of two different sizes, themselves subdivided by dark green syenite pillars. Behind these runs a vaulted ambulatory that supports the upper gallery. The arcaded arches are topped by gables sculpted to commemorate the confederated nature of Canada and they support one side of the hall's fan vaulted ceiling with carved bosses, while the other side rests on a single column in the centre of the room. This column is borne on a stone carved with an image of Neptune amongst sea lions and fish in a mythical sea. It was placed at noon on 2 July 1917, to mark the 50th anniversary of Confederation, and above it was carved the words:

1867 July 1917 On the fiftieth anniversary of the Confederation of British Colonies in North America as the Dominion of Canada the Parliament and People dedicate this Building in process of reconstruction after damage by fire as a memorial of the deeds of their Forefathers and of the valour of those Canadians who in the Great War fought for the liberties of Canada, of the Empire and of Humanity.

Around the central column is an inlaid marble floor with a 16-point windrose of Verde Antique serpentine from Roxbury, Vermont, and a swirl pattern of green serpentine from the Greek island of Tinos, embedded in Missisquoi Boulder Grey marble, from Philipsburg, Quebec. The overall pattern represents the essential element of water, alluding to Canada's motto: a mari usque ad mare (from sea to sea). The inner and outer circles of the floor are made of a Missisquoi Black marble from Philipsburg, Quebec, and white travertine from Italy, as well as Verde Antique serpentine separated by a band of Missisquoi Boulder Grey marble.