Canadian building code question

What are the building code requirements for townhouse construction in Canada?

Townhouse construction requires fire separations between units, minimum sound transmission class ratings for party walls and floors, independent egress from each unit, and structural independence or fire-rated connections between units. The applicable provisions depend on the number of units, building height, and whether the project falls under Part 9 or Part 3.

Townhouses are one of the most common residential building types in Canada and sit at a critical intersection of Part 9 and Part 3 code requirements. The fire separation, sound transmission, and egress provisions between units are the most consequential requirements because failures affect both life safety and occupant livability. Confirm the unit count, building height, and applicable code part early in design.

What to check first

  • Party walls between townhouse units must provide a minimum fire-resistance rating and are typically required to extend to the underside of the roof deck.
  • Sound transmission class ratings for party walls and floors must meet the minimum STC required by the applicable code.
  • Each unit must have independent egress that does not pass through another unit.

Jurisdiction notes

National baseline

The NBC Part 9 covers most townhouse construction. Part 3 applies when the building exceeds the Part 9 size and height limits.

Province and edition check

Provincial adoption may amend fire separation ratings, STC requirements, and the threshold between Part 9 and Part 3 application.

Municipal requirements

Zoning bylaws govern setbacks, lot coverage, unit density, and parking for townhouse developments.

Work through it in this order

  1. Determine the number of units, building height, and building area to confirm whether Part 9 or Part 3 applies.
  2. Review the fire-resistance rating requirements for party walls, floors, and ceilings between units.
  3. Verify the STC rating requirements for party walls and floor/ceiling assemblies.
  4. Confirm that each unit has independent egress that does not require passing through another unit.
  5. Check structural independence requirements and any fire-rated connection provisions.
  6. Review provincial and municipal requirements for parking, accessibility, and energy performance.

Common questions

What fire rating is required for townhouse party walls?

The NBC sets a minimum fire-resistance rating for party walls between townhouse units. The specific rating depends on the code edition, provincial adoption, and whether the building falls under Part 9 or Part 3.

What STC rating is required between townhouse units?

The code specifies a minimum sound transmission class rating for party walls and floor/ceiling assemblies. The specific value depends on the applicable code edition and provincial adoption.

Can townhouse units share a common exit?

Each townhouse unit typically requires independent egress. Common exits or shared corridors may be permitted in some configurations, but this depends on the occupancy classification and building height.