Canadian building code question

What are the building code requirements for mass timber construction in Canada?

The NBC permits mass timber construction up to 12 storeys under specific construction types, with requirements for encapsulation, fire-resistance ratings, connection protection, and sprinkler systems that vary by the level of exposed timber permitted.

Mass timber construction — including cross-laminated timber (CLT), glulam, and other engineered wood products — has been permitted in taller buildings under recent NBC amendments. The code introduces new construction types that allow mass timber in buildings up to 12 storeys with detailed requirements for fire protection, encapsulation, structural fire resistance, and connection design.

What to check first

  • Encapsulated mass timber construction (EMTC) requires all mass timber elements to be protected by non-combustible encapsulation materials.
  • Exposed mass timber construction permits limited areas of exposed wood surfaces with additional fire-protection requirements.
  • All mass timber buildings above traditional combustible-construction height limits require sprinkler protection and enhanced fire-resistance ratings.

Jurisdiction notes

National baseline

NBC 2020 amendments introduced construction types for encapsulated mass timber (EMTC) up to 12 storeys, with fire-resistance and encapsulation requirements in Part 3 Division B.

Provincial adoption

British Columbia was an early adopter of tall wood building provisions. Ontario and other provinces have adopted or are in the process of adopting the NBC mass timber amendments.

Project-specific variables

The permitted height, degree of exposed timber, connection fire-protection requirements, and testing standards all depend on the specific construction type selected.

Work through it in this order

  1. Determine whether the proposed building qualifies for a mass timber construction type based on occupancy, height, and area.
  2. Select the appropriate construction type (encapsulated or exposed mass timber) and verify all fire-resistance rating requirements.
  3. Confirm encapsulation requirements for structural elements, connections, and concealed spaces.
  4. Verify sprinkler system, fire alarm, and detection requirements specific to mass timber construction.
  5. Check provincial adoption status and any amendments to the NBC mass timber provisions.

Common questions

How tall can a mass timber building be in Canada?

Under the NBC 2020 amendments, encapsulated mass timber construction is permitted up to 12 storeys, subject to occupancy, area, fire-protection, and encapsulation requirements.

What is the difference between encapsulated and exposed mass timber?

Encapsulated mass timber requires all structural timber to be covered by non-combustible encapsulation. Exposed mass timber permits limited visible wood surfaces with additional fire-protection measures.

Are sprinklers required in mass timber buildings?

Yes. All mass timber buildings constructed under the taller-building construction types require sprinkler protection throughout.