Ottawa, June 27 -- Canada has launched an independent national design-and-build competition to rehabilitate and modernise 24 Sussex Drive, the official residence of the country's prime minister, after decades of deferred maintenance left the historic property unoccupied and in critical condition.

Prime Minister Mark Carney announced the initiative on Friday, saying the project aims to restore the landmark as a secure, accessible, sustainable and functional official residence while preserving its heritage character.

The competition will be open to eligible Canadian firms, with the Royal Architectural Institute of Canada (RAIC) advising on the competition framework and convening an independent jury chaired by renowned Canadian architect M...