Nuria's White Head by Jaume Plensa is exhibited in Paris. The Spanish artist is creating a three-storey sculpture of a human head for the courtyard of Encana's Bow tower in Calgary. ((Canadian Press))

Calgary's largest piece of public art will grace Western Canada's tallest building when Encana's Bow tower opens in 2012.

A three-storey sculpture of a human head has been commissioned from world-famous Spanish artist Jaume Plensa for the courtyard of the tower in the city's downtown, officials confirm.

Plensa is reported to be working on the piece — entitled Wishing Well — at an art gallery in Chicago. 

News of the giant artwork has created a buzz in Calgary's art community, said Gord Ferguson, who runs the sculpture program at the Alberta College of Art and Design.

'I think this is going to be one of those pieces that people will travel to see.'—Gord Ferguson

"I think this is going to be one of those pieces that people will travel to see. It will become a thing that Calgary's known for," he said.

Getting Calgarians to embrace works by Spanish artists has proven to be a hard sell — Santiago Calatrava's Peace Bridge being built across the Bow River has been controversial from the start.

Plensa's sculpture will likely also be provocative, but that's a good thing, according to Ferguson.

Calgary resident Vanessa Laine agreed.

"I like that idea. I think that also maybe reflects Calgary's forward thinking," she said.

The most difficult task for Encana might be trying to keep the enormous sculpture hidden until the Bow's grand opening in 2012, Ferguson said.

Located on two blocks of Centre Street and 5th and 6th Avenues S.E., the Bow was budgeted to cost about $1.5 billion.

The 58-floor headquarters for Encana and Cenovus Energy will be the tallest office building in Canada outside Toronto.