School of Architectural Technology

Faculty of Applied Science and Technology

ARCH34231 - ARCHITECTURAL STUDIO 6

MODULE 7: ONTARIO BUILDING CODE PART 3 ISSUES

"This module is intended to be nothing more than an introduction.  Once you have schematic designs for your projects, you would be in a position to do a Building Code Matrix which will analyze your particular building.  Nevertheless, to be forewarned to to be forearmed!    This will highlight those parts of the code that might have an impact on your planning phase."

Contents

1. Issues related to Multiple Occupancies
2. Classification under 3.2.2.
3. Exit requirements for an assembly building
4. Issues Related to Construction
5. Standard OBC 2006 Matrix for Part 3

Note: The 2015 OBC changes are required to be followed, and are far reaching:

Highlights include:

• increased door width requirements in barrier-free path of travel
• additional requirements for universal washrooms (equipment)
• clarification of access to toilets in rooms and stalls
• increased fire alarm requirements
• increased turning diameters and stall sizes for barrier-free access

These summares should help:

2015 OBC Changes

2015 OBC Diagrams

1. Issues related to Multiple Occupancies

a) Occupancy Choice

Table 3.1.2.1.: Every building or part of a build is to be classified according to its major occupancy as belonging to one of the Groups or Divisions described in Table 3.1.2.1.  It is sometimes useful to refer to the appendices of the code for clarification on what the classification is, or of a particular use.

Table 3.1.2.1.

This document may help:

Occupancy Classifications Word document.

b) Major Occupancy Choice

Definitions in 1.4.1.2.: "principal occupancy for which a building or a part of a building is use and is deemed to include the subsidiary occupancies that are an integral part of the principal occupancy."

Just because you have "ancillory spaces" that are also Major Occupancies as described in 3.1.2.1., it does not mean they have shared responsibilities. One occupancy must govern, and that is what you choose.

c) Separations Between Major Occupancies

This table below should be familiar to you by now. The fire separations between adjoining occupancies require Fire-resistance Ratings. Be careful of passageways (doors) or interior screens (windows) you might place in these separations. Percentages of openings requiring "rated closures" are restricted to certain amounts (3.1.8.4 and 3.1.8.6 covers the requirements).

Table 3.1.3.1

d) Openings in Floor Areas

Activities not in the same classification often need to be fire separated from each other.   The required ratings are provided in the above Table 3.1.3.1.  These relate to walls and separating floors BUT certain floor openings as outlined in 3.2.8. are acceptable. Interconnected Floor Spaces can be done in your work, but they must follow the rules! 3.2.8.3. outlines some of these rules very simply.

Fire Resistance Rating of Floors - Superimposed Major occupancies. (3.2.2.7.)

Superimposed Major Occupancies (except where one is less than 10% of the building area and NOT an F1 nor an F2 occupancy) the FRR (not the fire separation!) required for the floor of the higher occupancy would be based on the 3.2.2. requirements for the lower occupancy.

2. Building Classification under 3.2.2.

a) Streets/ Fire Truck Access

For some classifications (usually combustible construction where not sprinklered) it is important to know from how many directions ("streets") the fire could be fought.  Generally speaking, according ot 3.2.2.10., a building is considered to face two streets where not less than 50% of the perimeter is within 15m  of a street and three streets where 75% of the perimeter is within 15m of a street. In relation to any of the classifications in 3.2.2., consider your bulding area maximum size depending on how many streets you face.

b) Fire Fighter Access

The requirements for fire truck access, if not a public street right-of-way, are laid out in paragraphs 3.2.5.5. and 3.2.5.6.

• not less than 3m nor further than 15m from main entrance or any required access opening
• min. 6m wide; 5m clear height; 12 centreline radius at curves
• turn around facilities where the access route is more than 90 m long
  

c) Definitions

Don't forget the definition of "storey": Definitions in 1.4.1.2. (related to 3.2.1.1.(4)). The space between a floor and the top of the floor above....or if there is no storey above, the ceiling of the floor. A mezzanine level need not be considered a storey provided it meets certain criteria.

Definition of "building area": Definitions in 1.4.1.2.  The greatest horizontal area of a building above grade.

d) Classification Choice

Classifications under 3.2.2. where multiple occupancies impact building use include:

• 3.2.2.4.
• 3.2.2.6.
• 3.2.2.7.
• 3.2.2.8.

Where there is more than one major occupancy the requirements for the most restricted major occupancy must be met. In a building where the aggregate of all major occupancies in a particular Group of Division is more than 10% of the floor area (except for the case of F1 and F2 occupancies).              

3.  Exit Requirements for an Assembly Occupancy

The following points summarizes those sentences which determine the number and location of exits in an assembly occupancy building.

• Number of Exits OBC 3.4.2.1. More than one exit must be provided for any floor area exceeding 150m2 (1610 s.f.) if area NOT sprinklered or 200m2 (2150 s.f.) if sprinklered. Separate exits by a minimal distance of half the diagonal of the area of the fire compartment.
• Distance to an exit OBC 3.4.2.5. If more than one exit is required from a floor area, the exits must be located so that at least one exit must be within 30m (98’-5")
• Definition of an exit  OBC 1.4.1.2. OBC 3.4.4.4.  An exit may be something other than an exterior door. It can be a fire-separated corridor or stairway. If this is the case your permitted travel distance is to the point where you enter this fire-protected zone. Note that the integrity of such a fire-separated corridor must be maintained. It cannot be used as access to a service room, and storage rooms, washrooms, laundry rooms etc. cannot open directly into an exit enclosure (a vestibule would be required).
• Exiting through a lobby  OBC 3.4.4.2.  ONE path of exit may be through a lobby provided that the lobby is not more than 4.5m (14’-9" above grade), the path through the lobby does not exceed 15m (49’-3"), industrial occupancies do not open off of the lobby (nor residential occupancies it the building is NOT sprinklered), the lobby, if double height does not include more than the main floor and the floor below, OR the main floor and the floor above.
• Mezzanine Exiting OBC 3.4.2.2.  One means of egress permissible, provided occupancy does not exceed 60 and area does not exceed 150m2 (1610 s.f.)
• Direction of door Swing OBC 3.4.6.11.     An exit door must swing in the direction of exit travel (i.e. outwards) where the occupant load it serves is greater than 60 persons.
• Exit Width OBC 3.4.3.4. To determine whether you are providing adequate widths for exiting, take the occupant load and multiply it by 6.1mm (1/4") for doorways, ramps and corridors, or 9.2mm (3/8") for stairs.
• Clear Heights of exits  OBC 3.4.3.5.  Every exit must have a headroom clearance of not less than 2100mm (6’-11"). Doors can be 2030 (6"-8").
• Min. no. of risers  OBC 3.4.6.2.  No flight of interior stairs should have less than three risers.
• Handrails OBC 3.4.6.4. Every exit stair or ramp requires at least one handrail, and where the width exceeds 1100mm (3’-7") handrails must be provided on both sides.
• Exposure of exits to fire OBC 3.2.3.13 Where a protected exit (ref. 3rd reference) provides egress to the face of a building, the walls of adjacent fire compartment must be rated for a distance of 3m (9’-10") each direction.

4. Issues Related to Construction

Heavy timber construction means that type of combustible construction in which a degree of fire safety is attained,
(a) by placing limitations on the sizes of wood structural members and on the thickness and composition of wood floors and roofs, and
(b) by the avoidance of concealed spaces under floors and roofs.

Table 3.1.4.7.

5. Standard OBC 2012 Matrix for Part 3

The "matrix" shown below will be provided to you for your reference, and ultimately your use, below   A second matrix which relates to Part 11 and is applicable only to work on existing buildings will be introduced in a later class, and also be provided. 

PART 3 MATRIX (January 2014): Word document and PDF document

The Building Departments of most municipalities will require a Building Code Matrix to be submitted along with the permit drawings when an application is being made for a building permit.   This is to ensure that someone who has qualifications related to building code issues has ensured that the project meets the requirements of the current OBC.