Calgary's Centennial Planetarium has reopened as a contemporary art gallery following a major CA$25m (US$18.9m, €17.2m) renovation.

Called Contemporary Calgary, the planetarium – which is known for its brutalist architecture and imposing concrete dome – had been vacant since 2011, following the opening of Calgary's TELUS Spark Science Centre. It was put out for expression of interest by the city of Calgary in 2013 when private donations and grants from both local and federal governments made its transformation into an art gallery possible.

The renovation, carried out by Gibbs Gage Architects and KPMB Architects, includes a new 10,000sq ft (929sq m) gallery, another 3,000sq ft (278sq m) gallery, a rooftop sculpture garden and event space, as well as a new entrance pavilion, café-style restaurant and open community spaces.

"When the city put this building out for an expression of interest in 2013, three longstanding arts organisations in the city of Calgary came together with one shared vision which was 'Let's bring a major contemporary art experience to the city of Calgary'", said Contemporary Calgary CEO, David Leinster.

"Because the building is kind of weird and wacky and wonderful, makes it all the more exciting to turn it into something else."

Bruce Kuwabara, partner at KPMB and design-lead on the project, said: "The re-imagination of the Centennial Planetarium – an icon of optimism – into a dynamic, game-changing cultural hub, is an ideal project of architecture in our time."

The gallery, which opened to the public on 23 January 2020, will house a series of travelling exhibitions, including Yoko Ono's Growing Freedom: The instructions of Yoko Ono and The art of John and Yoko, in place of fixed collections, and is currently hosting Luke Jerram's Museum of the Moon exhibit – a scale model of the Moon suspended from the top of the dome.

The gallery will offer extended opening hours, - Tuesday to Sunday 11am - 6pm and 9pm on Thursdays - and has announced a new admissions policy, offering a CA$10 (US$7.62, £5.82) admission fee or an annual membership of CA$20 (US$15.24, £11.64), to make it one of the most accessible galleries in the region.