[3] The walls, supported by a ring of 16 flying buttresses, are loadbearing, double-wythe masonry, consisting of a hydraulic lime rubble fill core between an interior layer of dressed stone and rustic Nepean sandstone on the exterior.

[5] The initial overall combination of colours—grey Gloucester limestone and grey Nepean, red Potsdam and buff Ohio sandstones, as well as purple and green slate banding—conformed to the picturesque style known as structural polychromy.

[6] The main reading room rises to a vaulted ceiling and the walls and stacks are lined with white pine panelling carved into a variety of textures, flowers, masks, and mythical creatures.

In the galleries are displayed the coats of arms of the seven provinces that existed in 1876, as well as that of the Dominion of Canada, and standing directly in the centre of the room is a white marble statue of Queen Victoria, sculpted by Marshall Wood in 1871.

It was then necessary to perform structural work, as well as to install a replica of the inlaid parquet floor and dismantle the wood panelling and ship it to Montreal for cleaning and partial fireproofing.

[10] The Centre, East, and West Blocks subsequently received extensive climate control and electrical upgrades, but the library was largely overlooked.

[15] Also done at the time was a nine-metre-deep excavation of the bedrock beneath the library building, in order to provide more storage space, mechanical areas, and a link to an existing loading dock.