The cost of relocating the Ontario Science Scentre to Ontario Place increased by $400 million in less than eight months, the province’s auditor general has found, throwing cold water on the government’s assertions that moving the tourist attraction would be cheaper than renovating the existing site.

When the Ford government announced a controversial plan to shutter and relocate the Ontario Science Centre in the spring of 2023, the province boasted that taxpayers would save $257 million, over a 50-year period, by closing the aging and poorly maintained site.

The preferred option, the government said, was to build a new science centre on the Ontario Place ground that, despite a smaller footprint, would fit all the “core programming” the science centre needs to meet its mandate.

A business case analysis suggested that keeping the science centre at the current site would cost $1.3 billion over 50 years, compared with $1.047 billion over 50 years to move it to Ontario Place.

While the government never updated that figure, Ontario’s auditor general found on Tuesday that the cost to build and maintain a new science centre at Ontario Place has increased by $397 million over that same 50-year period — a 47 per cent increase from the original estimated cost approved by the government.

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“If these costs are added to the $1.047 billion the total is now $1.444 billion,” the auditor found.

The increased costs are due to a $244 million increase in design and construction costs, a $93 million increase in life cycle and maintenance costs and an $80 million increase in costs due to changes to the building and cost escalations.

Click to play video: '‘No other choice’: Ontario Science Centre permanent closure imminent'

The latest financial snapshot available, however, is from November 2023 — meaning the costs may have increased over the past year.

The auditor notes that the price tag of rehabilitating the existing science centre would have also increased, but didn’t specify by how much.

The auditor recommended that the Ministry of Infrastructure should provide Ford’s cabinet with the “full cost implications” to allow the province to make a sound decision.

The ministry accepted the recommendation.