Adding equipment inside a building means analyzing how the new loads will be distributed across the structure and ensuring the proposed configuration complies with the national building code. Structural engineers must carefully assess whether the new configuration calls for a full structural analysis of the building or if a localized assessment is sufficient. Section 10 of the Québec Construction Code, which adapts the National Building Code of Canada for provincial requirements, clearly outlines surface load or mass distribution constraints that may require seismic upgrades to the building's lateral load-resisting system.

For example, consider an aging piece of outdoor equipment located on the roof of an existing building. Since increasing its processing capacity is unnecessary, it can be replaced by a similar unit. However, the new equipment has a different geometry and occupies a slightly larger roof area. Furthermore, a review of the original design documents reveals that roof snow loads were never reassessed. The existing equipment has been in place for 20 years without any observed structural issues under snow loads.

Structural engineers frequently encounter such scenarios on industrial projects. They must carefully evaluate when a local analysis of new loads is insufficient to comply with National Building Code requirements. Structural engineers play a crucial role in ensuring all stakeholders fully understand project constraints.

BBA's team of structural experts has extensive experience with these projects and the applicable codes. These include the Québec Construction Code and American standards such as the Federal Emergency Management Agency (FEMA) and the American Society of Civil Engineers (ASCE), which may serve as guidelines, depending on the structure type and work required. Our experts make it their duty to inform project developers so they can assess and understand the technical, financial and legal implications of their projects properly and account for all potential impacts, including costs.

For more information, contact our experts:

• Bertrand Comeau, Principal Engineer, Structural Engineering, Montreal office
• Nicolas Samson, Senior Engineer, Structural Engineering, Montreal office

American Society of Civil Engineers, Seismic Evaluation and Retrofit of Existing Buildings, ASCE41-17

National Research Council of Canada, National Building Code 2020 (model code)

National Research Council of Canada, Guideline for Seismic Upgrading of Building Structures

Federal Emergency Management Agency, NEHRP Guidelines for the Seismic Rehabilitation of Buildings – FEMA 273

Régie du bâtiment du Québec, Quebec Construction Code, Chapter 1 – Building (NBC 2015 amended – Quebec), in effect since January 8, 2022