A team of engineers has re-evaluated the threat earthquakes pose to more than 500 B.C. schools and determined 152 remain at high risk and will need structural upgrades to make them safe.

The total cost of the repairing the 152 high-risk schools has been estimated at $1.3 billion dollars. The remaining schools have been classified as medium or low risk, meaning they can be made safe without structural upgrades.

The team, which included engineers from UBC's department of civil engineering and the Association of Professional Engineers and Geoscientists of B.C. used new assessment tools and procedures to predict how different sections of school buildings in different seismic zones would withstand different types of earthquakes.

In 2005, a provincial report identified 750 schools across B.C. in need of seismic upgrades to survive a major earthquake, prompting the government to pledge $1.5 billion to fix the problems.

Since then B.C. government has spent about half a billion dollars upgrading 132 schools.