National Building Code Standards: Building Classification and Part 9 Application Guide

Understanding the National Building Code is critical for ensuring safety and compliance in every project. At empcontracting.ca Inc. your construction contractor in London, Ontario, we specialize in navigating these complex regulations to deliver high-quality, code-compliant structures.

Application of Part 9: Small Buildings and Residential Standards

Part 9 of Division B governs buildings that are 3 storeys or less in height with a building area not exceeding 600 m². These standards apply to several occupancy types, which are vital for residential and commercial development in the London area.

Key Occupancy Classifications under Part 9:

Group B, Division 4: Home-type care occupancies.
Group C: Residential occupancies (standard housing).
Group D: Business and personal services.
Group E: Mercantile occupancies.
Group F, Divisions 2 and 3: Medium- and low-hazard industrial occupancies.

Part 10: Guidelines for Alterations to Existing Buildings

When renovating or altering an existing structure, Part 10 standards apply. However, empcontracting.ca Inc. your construction contractor in London, Ontario, notes that several exceptions exist where Part 10 does not apply, including:

Farm buildings and construction camps.
Tents and air-supported structures.
Relocatable buildings and specific storage garages.
Heritage Buildings: Structures formally recognized for their heritage value by municipal or federal authorities.

Determining Building Size and Fire Separation

The code provides specific rules for how building size is calculated, particularly when firewalls are involved. If a firewall divides a building, each portion is generally considered a separate building.

Vertical Fire Separations

Portions of a building can be considered separate entities for height determination if they are separated by a vertical fire separation with at least a 1-hour fire-resistance rating. This is permitted if:

The portion is not more than 4 storeys in height.
The occupancy is limited to assembly, residential, or business services.
Firefighters have an unobstructed path of travel within 45 meters from the street.

Agricultural Occupancies and Part 2 Applications

For agricultural projects in Southwestern Ontario, Part 2 applies to buildings exceeding 600 m² or 3 storeys. Agricultural occupancies (Group G) are classified based on occupant load; buildings with no more than one person per 40 m² fall under Divisions 1 through 4 of Group G. Whether you are building a large-scale facility or a specialized agricultural structure, empcontracting.ca Inc. your construction contractor in London, Ontario, ensures your project meets all Division A and B requirements.