West Block is the oldest building on Parliament Hill in Ottawa, but it has never been the most important.

That changes next year: the House of Commons is moving in.

The Parliament buildings were first constructed in the lead-up to Confederation in 1867. Political representatives from the new country needed a place to gather and debate the issues of the day. The centrepiece of Parliament Hill is Centre Block, which features such icons as the Peace Tower, the Library of Parliament, the House of Commons and the Senate. Flanking Centre Block on either side is East Block and West Block, which both contain offices and meeting rooms. Other government buildings have been added over the years nearby.

Despite occasional repairs – including the full-scale rebuilding of Centre Block after a fire in 1916 – the buildings are showing their age. In 2007, the federal government decided on a long-term project to repair the crumbling offices from the inside out, replacing everything from the copper roofs to the electrical systems.

Because politicians still needed Parliament Hill to carry out their duties, the Parliament buildings couldn’t all be shut down at once. Instead, the restoration work has been tackled in stages, beginning with West Block’s closure in 2011.

Centre Block is next, and is expected to be closed for at least a decade. And, while it is, the House of Commons has to move – about 100 metres to the west, to the newly remodeled West Block, which is set to open in January, 2019.

This is the story of how the new West Block was made.