Mecanoo proposals to revamp the B-listed hall include two new entrances linked with an interior vennel space, a 70-cover licensed cafe, a three-story pavilion as part of the main hall and a second floor gallery.

The original entrance area will become a key part for the permanent gallery, with two grand staircases linking collections on the ground and first floors.

The Dutch practice was selected by a panel from Perth & Kinross Council in August 2017 following an international design competition which drew more than 70 initial expressions of interest from across the world.

Funding for the project was confirmed through the Tay Cities Deal at the end of last year.

Perth City Hall, which was built in 1911, has lain empty for 14 years.

Perth and Kinross Council leader Murray Lyle said it was now “full steam ahead” for the development, which is expected to take two years to complete.

He said: “The former City Hall is a key landmark in the heart of Perth, and its transformation is a high-profile example of the ongoing cultural transformation of the city.”

Mr Lyle added: “Combined with the ongoing work to transform St Paul’s Church and the recently unveiled plans to create a new public space at Guard Vennel, we’re sending a clear message to businesses, visitors and residents that we are committed to investing in Perth city centre as a place to enjoy food, music, art and heritage.”

BAM Construction will work with hub East Central Scotland to redevelop the Edwarian building, with construction expected to start work in 2019 and the grand opening scheduled for 2021.

The contractor will also lead the £10m Hoskins Architects-designed revamp of Perth Museum and Art Gallery with Ogilvie Construction tasked with building the new collection store on a separate site.

London-based design practice Metaphor has been appointed as the “interpretation and exhibition designers” for both venues and will work with the respective architects to develop new interiors and exhibition spaces and bring the stories of Perth’s Ancient Roots and its Modern Scots to life.