Demolition of the former Leamington District Secondary School starts Monday.
The Municipality of Leamington said the demolition will be done in phases, starting with the gymnasium, which was damaged in a recent fire.
The municipality hired a contractor to test the area for hazardous materials, including asbestos. None were found.
Each demolition phase will be tested to ensure compliance with safety and environmental regulations.
Before the fire, Leamington announced a deal with Amico Properties to build affordable housing on the site had fallen through. The municipality said tearing down the former school is part of its long-term plan for the site.