Understand the information duty
Ontario explains that project owners must determine whether designated substances are present and prepare a list. The information must be shared with the prospective constructor before the relevant binding contract. The constructor also has information-sharing duties. Consult the official guidance for the application to your project.
Make the scope of the investigation match the work
Tell the person assessing materials what will be disturbed, including hidden layers or service areas. Keep any inaccessible areas and assumptions visible. A report for an earlier renovation may not cover the current rooms or depth of removal.
Use the findings to shape the demolition scope
Ask which findings affect the proposed work and what specialist assessment or handling is required. Do not guess from a material’s appearance or use a demolition photograph as evidence that testing is unnecessary. Keep the report and any updates available to the parties planning the work.
Bring these details to the conversation
Keep these items together so the people assessing the work are looking at the same scope.
- Removal drawings or a room list
- Existing reports and their limitations
- Areas that could not be assessed
- Questions for the assessor and contractor
Official information
Check the applicable requirements for your property and proposed work with the responsible authority or qualified professional.
Source references reviewed October 5, 2026.