Scope
Part 3 governs buildings outside Part 9 limits
Use this calculator when the building exceeds Part 9 limits — i.e., greater than 3 storeys, greater than 600 m² building area, or contains an occupancy not allowed under Part 9 (Group A, B, F1, etc.). The calculator returns the matching §3.2.2.X classification plus the required FRRs, combustible/noncombustible permission, and key fire separation rules.
1 · Your Unit's Major Occupancy
Per Subsection 3.1.2.
2 · Neighbouring Occupancies
Drives mixed-occupancy separations per Table 3.1.3.1.
3 · Building Size & Sprinklers
Drives §3.2.2.X classification
Building Classification
Required Fire-Resistance Ratings
Floors / Mezzanines
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Roof
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Loadbearing Walls / Cols.
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4 · Permitted Construction Type
Combustible vs. noncombustible per §3.2.2.X
Combustible construction permitted (heavy timber / wood-frame, encapsulated mass timber where applicable)
Noncombustible construction required or permitted
5 · Required Fire Separations
Suites, public corridors, mezzanines, exits
6 · Firewalls & Other Structural Elements
§3.1.7 to §3.1.11
Firewall (§3.1.8)
A firewall is required to separate buildings under one roof, or to subdivide a single building into separate buildings for code purposes.
· Firewall FRR: 2 h minimum — 4 h if separating a Group F1 high-hazard occupancy or where the height/area of either building requires it.
· Firewall must be of noncombustible construction and have structural sufficiency to remain after collapse of construction on either side.
· Firewall FRR: 2 h minimum — 4 h if separating a Group F1 high-hazard occupancy or where the height/area of either building requires it.
· Firewall must be of noncombustible construction and have structural sufficiency to remain after collapse of construction on either side.
3.1.8.2. · 3.1.8.3.
Mezzanines (§3.1.10)
A mezzanine in a sprinklered building need not be considered a storey if its area does not exceed 40 % of the floor area of the room or floor in which it is located. Mezzanine FRR is generally the same as the floor of the storey containing it — see classification.
3.2.1.1. · 3.1.10.
Spatial Separation (§3.2.3)
Exterior walls require an FRR and limits on unprotected openings based on limiting distance and exposing building face area. Required FRR ranges from 0 to 2 h; openings may be 0 % to 100 % allowed depending on the table used.
3.2.3.1. · Tables 3.2.3.1.-A through -E
Exit Stair Shafts (§3.4.4)
Vertical exit shafts must be enclosed in a fire separation with an FRR not less than the floor assemblies they connect, and not less than 45 min in any case. In high buildings, additional pressurization and signage requirements apply per §3.2.6.
3.4.4.1. · 3.2.6.
7 · Compliance Pathways for the Required FRR
How to demonstrate the rated assembly
Test methods
FRR demonstrated through CAN/ULC-S101 / ULC standards. Use a listed proprietary assembly (cULC, UL, GA file numbers) that matches or exceeds the required rating, and that is appropriate for the construction type.
3.1.7.1.
Calculation method (Appendix D)
Component additive method per Appendix D-2. Common for typical wood-frame assemblies and for mixed-membrane systems where no listed design exists.
3.1.7.1. · Appendix D
Generic descriptions
Tables in Appendix D-2 provide generic FRRs (concrete, masonry, steel, gypsum board, timber). Useful for preliminary sizing.
Appendix D-2
Encapsulated Mass Timber
For combustible-permitted classifications, mass timber per 3.2.2.48 (12-storey EMT) and other articles requires gypsum encapsulation in addition to the FRR. See specific §3.2.2.X article for encapsulation details.
3.2.2.48. · 3.1.6.