Canada · Building types

What are the building code requirements for stacked townhouses in Canada?

Stacked townhouses must meet building code requirements for fire separation between units both horizontally and vertically, independent egress for each dwelling unit, and structural design for the combined loading. The Part 3 vs. Part 9 classification depends on overall building height and area.

Stacked townhouses — where dwelling units are arranged both side-by-side and vertically — are an increasingly common building form in Canadian urban development. Their unique configuration creates distinct code compliance challenges for fire separation, egress, and structural design that differ from conventional townhouses.

What to check first

  • Fire separations must address both horizontal party walls and vertical floor assemblies between stacked units.
  • Each dwelling unit must have independent egress to the exterior without passing through another unit.
  • Stacked configurations often trigger Part 3 classification due to the combined building area or height.

Jurisdiction notes

NBC baseline

The National Building Code addresses stacked townhouses through its general provisions for multi-unit residential buildings. The Part 9 vs. Part 3 threshold is critical for determining applicable requirements.

Provincial variations

Provincial code adoptions may include specific provisions for stacked townhouse configurations, particularly regarding fire separation and egress.

Municipal planning

Stacked townhouses are a zoning-permitted form in many municipalities as part of gentle density initiatives. Zoning approval is required in addition to building code compliance.

Not professional advice

CodeCan reports what the published building code says. It is not legal, engineering, or architectural advice, and it does not certify compliance. Building codes are adopted and amended provincially and enforced locally — always verify with your authority having jurisdiction (AHJ) before you build.

Work through it in this order

  1. Determine whether the stacked townhouse project falls under Part 9 or Part 3 based on overall height and area.
  2. Design fire separations between all adjacent units — both horizontally and vertically — to meet required ratings.
  3. Provide independent egress for each unit with exit access that does not pass through adjacent dwelling spaces.
  4. Address sound transmission requirements for both party walls (STC) and floor assemblies (STC and IIC).
  5. Ensure structural design accounts for the combined loading of stacked units and any cantilevers or setbacks.

Common questions

What fire separation is required between stacked townhouse units?

Fire separations are required between all adjacent dwelling units, both horizontally and vertically. The required rating depends on the applicable code Part and construction type.

Do stacked townhouses fall under Part 9 or Part 3?

The classification depends on the overall building height and area. Stacked configurations that exceed Part 9 thresholds must comply with Part 3, which imposes more complex requirements.

How do upper units in stacked townhouses exit the building?

Upper units typically exit via exterior stairs, common corridors, or enclosed stairways. The egress path must be independent and code-compliant.