A sharp jump in the budget for expanding the St. John's Convention Centre will put no burden on taxpayers, a councillor says.

The city has awarded the contract for expanding the convention centre to Pomerleau Inc., which had the lowest bid at just under $52.7 million.

The project was launched in 2011 with a $45-million budget, cost-shared equally between St. John's and the federal and provincial governments.

But Coun. Sandy Hickman insists taxpayers will not be left with the extra costs.

"The people that are going to pay for this, for the city's portion, will be actually [the] people that come and stay in hotels in the city. The room tax will be used entirely to pay for construction costs," Hickman told CBC News.

The expanded convention centre will be almost twice the size as the current one. Work is expected to begin immediately on the project.

Hickman said the city would like expansion to be finished to handle conventions in the spring of 2016. The existing centre will stay open until the fall of 2014, when it will need to close to accommodate construction crews.

Hickman maintains that the project will pay for itself.

"The economic impact would probably be a third to 50 per cent more convention business for the city as we get rolling out into [2017], -18, -19," he said.

Hickman said the Convention Centre generates between $30 million and $35 million each year in economic activity. He said that figure is expected to expand to a range of $50 million to $60 million.