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The Ontario Building Code | Group C, up to 3 Storeys

3.2.2.47. Group C, up to 3 Storeys

(1) A building classified as Group C is permitted to conform to Sentence (2) provided,

Note: On July 1, 2017, Sentence 3.2.2.47.(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. 22 (1))

(a) it is not more than 3 storeys in building height, and

(b) it has a building area not more than the value in Table 3.2.2.47.

Table 3.2.2.47.
Maximum Building Area, Group C, up to 3 Storeys

Forming Part of Sentence 3.2.2.47.(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

1 800

2 250

2 700

2.

2

900

1 125

1 350

3.

3

600

750

900

(2) The building referred to in Sentence (1) is permitted to be of combustible construction or noncombustible construction used singly or in combination, and,

(a) except as permitted by Sentences (3) and (4), floor assemblies shall be fire separationswith a fire-resistance rating not less than 45 min,

(b) mezzaninesshall have, if of combustible construction, a fire-resistance rating not less than 45 min, and

(c) 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, that are entirely contained within these dwelling units, shall have a fire-resistance rating not less than 45 min but need not be constructed as fire separations.

(4) In a building in which there is no dwelling unit above another dwelling unit, the fire-resistance rating for floor assemblies entirely within the dwelling unit is waived.

(5) A retirement home regulated under the Retirement Homes Act, 2010 shall be sprinklered.

Note: On July 1, 2017, Sentence 3.2.2.47.(5) of Division B of the Regulation is revoked. (See: O. Reg. 139/17, s. 22 (2))

In Plain Language

This article sets one of the specific size-and-construction packages available for a Group C buildings building: up to 3 storeys, area per Table 3.2.2.47 (unsprinklered baseline), combustible or noncombustible construction. 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.