NDP education critic Trent Wotherspoon says there are no hard numbers to back up the government's claim that building the schools in bulk through the public-private partnership will be less expensive.
Wotherspoon says there needs to be more information on the full cost to taxpayers.
The schools would be joint-use — meaning public on one side and Catholic on the other with shared spaces such as gymnasiums or daycares in the middle.
Premier Brad Wall has said traditional construction costs would be about $450 million, but the P3 could save $30 million.
Infrastructure Minister Don McMorris says it's tough to pinpoint exactly how much money will be saved, but he says the estimate is based on a similar approach to building schools in Alberta.