The Ontario Building Code | Group C, up to 4 Storeys, Noncombustible Construction
3.2.2.44. Group C, up to 4 Storeys, Noncombustible Construction
(1) A building classified as Group C is permitted to conform to Sentence (2) provided,
Note: On July 1, 2017, Sentence 3.2.2.44.(1) of Division B of the Regulation is amended by adding "other than a retirement home" after "Group C" in the portion before Clause (a). (See: O. Reg. 139/17, s. 18)
(a) it is not more than,
(i) 3 storeys in building height, or
(ii) 4 storeys in building heightprovided there is not more than one dwelling unit above another dwelling unit, and vertical fire separationsof adjacent dwelling units conform to Sentence (4), and
(b) it has a building area not more than the value in Table 3.2.2.44.
Table 3.2.2.44.
Maximum Building Area, Group C, up to 4 Storeys
Forming Part of Sentence 3.2.2.44.(1)
| Item | Column 1 | Column 2 | Column 3 | Column 4 |
|
| No. of Storeys | Maximum Area, m2 |
|
|
|
|
| Facing 1 Street | Facing 2 Streets | Facing 3 Streets |
| 1. | 1 | not limited | not limited | not limited |
| 2. | 2 | 6 000 | not limited | not limited |
| 3. | 3 | 4 000 | 5 000 | 6 000 |
| 4. | 4 | 3 000 | 3 750 | 4 500 |
(2) The building referred to in Sentence (1) shall be of noncombustible construction, and,
(a) except as permitted by Sentence (3), floor assemblies shall be fire separations with a fire-resistance rating not less than 1 h,
(b) mezzaninesshall have a fire-resistance rating not less than 1 h,
(c) roof assemblies shall have a fire-resistance rating not less than 1 h, and
(d) loadbearingwalls, columns and arches shall have a fire-resistance rating not less than that required for the supported assembly.
(3) In a building that contains dwelling units that have more than 1 storey, subject to the requirements of Sentence 3.3.4.2.(3), the floor assemblies, including floors over basements, which are entirely contained within these dwelling units, shall have a fire-resistance rating not less than 1 h but need not be constructed as fire separations.
(4) The dwelling units described in Subclause (1)(a)(ii) shall be separated by continuous vertical fire separations that extend through all storeys and service spaces of the separated portions.
(5) A retirement home regulated under the Retirement Homes Act, 2010 shall be sprinklered.
Note: On July 1, 2017, Sentence 3.2.2.44.(5) of Division B of the Regulation is revoked. (See: O. Reg. 139/17, s. 19)
In Plain Language
This article sets one of the specific size-and-construction packages available for a Group C buildings building: up to 4 storeys (or up to 4 with restrictions on stacked dwelling units), noncombustible construction, area per Table 3.2.2.44. Designers can choose whichever of the several packages in this Subsection best fits the building being planned, trading height and area against construction type, sprinklering, and fire-resistance rating requirements.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.