Citation : Liggio v. Pucci 2022 ONBCC 15
Ruling No.: 22-15-1607
Application No.: B-2022-04
BUILDING CODE COMMISSION
IN THE MATTER OF Subsection 24(1) of the Building Code Act, S.O. 1992, c. 23, as amended.
AND IN THE MATTER OF Sentence 3.1.8.7.(2), Subclause 3.1.8.8.A.(2)(a)(iii) and Sentence 3.2.6.2.(5.1) of Division B of Regulation 332/12, as amended, (the “Building Code”).
AND IN THE MATTER OF an application by Carmela Liggio, for the resolution of a dispute with Ben Pucci, Chief Building Official, to determine whether the proposal to waive the requirement for smoke dampers at the air-transfer opening locations of the residential public corridors of Building A/B and Building C/D, on the basis that the corridor make-up air system forms part of a smoke control system, provides sufficiency of compliance with Sentence 3.1.8.7.(2), Subclause 3.1.8.8A.(2)(a)(iii) and Sentence 3.2.6.2.(5.1) of Division B of the Building Code at 7950 Bathurst Street and 8 Beverley Glen Boulevard, Thornhill, Ontario.
APPLICANT Carmela Liggio
Senior Development Manager
The Daniels Corporation
Toronto, Ontario
RESPONDENT Ben Pucci
Chief Building Official
City of Vaughan, Ontario
PANEL Alison Orr, Chair Designate
Christina Kalt
Albert Schepers
PLACE via Teams Video Conference
DATE OF HEARING July 12, 2022
DATE OF RULING August 15, 2022
APPEARANCES Sumeet Ahluwalia
Senior Development Manager
The Daniels Corporation
Toronto, Ontario
Agent for the Applicant
Matteo Gilfillan
President
Matteo Gilfillan & Associates
Toronto, Ontario
Agent for the Applicant
Brent Whitby
Partner
Kirkor Architects and Planners
Toronto, Ontario
Agent for the Applicant
Dean Brown
Deputy Chief Building Official
City of Vaughan, Ontario
Designate for the Respondent
Uma Manohara
Senior Plans Examiner
City of Vaughan, Ontario
Designate for the Respondent
Michaela Tataru
Building Engineer
City of Vaughan, Ontario
Designate for the Respondent
RULING
1. Particulars of Dispute
The Applicant applied for a building permit under the Building Code Act, 1992, to construct four residential towers of varying heights (Buildings A, B, C and D) with an at-grade retail component at 7950 Bathurst Street and 8 Beverley Glen Boulevard, Thornhill, Ontario.
Buildings A and B form one building according to the Building Code, connected on Levels 1 to 6 via a common podium. Buildings C and D form a second building according to the Building Code, connected on Level 1. Buildings A/B and C/D are also considered high rise structures as per Subsection 3.2.6. of Division B of the Building Code. The heights of the proposed residential towers are as follows: 15 storeys for Building A, 25 storeys for Building B, 12 storeys for Building C and 6 storeys for Building D. The below-grade parking garage is designed as a separate building (i.e. in accordance with Article 3.2.1.2. of Division B of the Building Code) but is considered to form part of Building A/B, with Building C/D being separated from the below-grade parking levels via vestibules that are pressurized or ventilated naturally to outside air.
These buildings are required to be provided with a fire alarm, sprinkler, and standpipe and hose system. There are mechanical supply air and return branch ductworks serving each public corridor located at each floor level.
The construction in dispute involves the requirement for smoke dampers at the air-transfer opening locations of the residential public corridors and whether the permission to waive the requirement for smoke dampers for noncombustible branch ductworks that penetrate the required fire separations at each floor level, as per Subclause 3.1.8.8A.(2)(a)(iii) of Division B of the Building Code, applies to this project.
2. Provisions of the Building Code in Dispute
Article 3.1.8.7. Location of Fire Dampers and Smoke Dampers
(2) Except as provided in Article 3.1.8.8A., a smoke damper or a combination smoke and fire damper shall be installed in conformance with Article 3.1.8.9A. in ducts or air-transfer openings that penetrate an assembly required to be a fire separation, where the fire separation,
(a) separates a public corridor,
(b) contains an egress door referred to in Sentence 3.4.2.4.(2)(c) serves an assembly, care, care and treatment, detention or residential occupancy, or
(d) is installed to meet the requirements of Clause 3.3.1.7.(1)(b) or Sentence 3.3.3.5.(4) or 3.3.4.11.(4).
Article 3.1.8.8A. Smoke Dampers Waived
(2) The requirement for smoke dampers or combination smoke and fire dampers described in Sentence 3.1.8.7.(2) is permitted to be waived for noncombustible branch ducts having a melting point above 760°C that penetrate a fire separation,
(a) provided the ducts,
(i) have a cross-sectional area not more than 130 cm² and serve only air-conditioning units or combined air-conditioning and heating units discharging air not more than 1.2 m above the floor,
(ii) extend not less than 500 mm inside exhaust duct risers that are under negative pressure and in which the airflow is upward as required by Article 3.6.3.4., or
(iii) are required to function as part of a smoke control system, or
(b) provided the fire separation separates a vertical service space from the remainder of the building and provided each individual duct exhausts directly to the outdoors at the top of the vertical service space.
Article 3.2.6.2. Limits to Smoke Movement
(5.1) Except as provided in Article 3.2.4.13. or as otherwise provided in this Part, air handling systems used to provide make-up air to public corridors serving suites in a Group C major occupancy shall not shut down automatically upon actuation of the fire alarm so as to maintain corridor pressurization.
3. Applicant’s Position
The Agent for the Applicant submitted that the air transfer openings of the air handling system used to provide make-up air to the public corridors serving the suites in a Group C major occupancy, is required to be designed to limit smoke movement as per Sentence 3.2.6.2.(5.1) of Division B of the Building Code, and is considered a part of a smoke control system. The Agent further submitted that the permission to waive the requirement for smoke dampers, as permitted by Sentence 3.1.8.8A.(2) of Division B of the Building Code for the openings serving the air handling system of the above-noted public corridor, is applicable.
According to the Agent, Sentence 3.2.6.2.(5.1) of Division B of the Building Code requires that, unless provided in Article 3.2.4.13 of Division B of the Building Code or otherwise provided in Part 3 of Division B of the Building Code, the air handling system used to provide make-up air to the public corridors serving the suites in a Group C major occupancy are not to shut down automatically upon actuation of the fire alarm in order to maintain corridor pressurization. The Agent further noted the make-up air unit would be provided with emergency power, in accordance with Clause 3.2.7.9.(1)(c) of Division B of the Building Code, and a switch would be provided in the central alarm and control facility to allow for firefighters’ operation of the make-up air unit, in accordance with Clause 3.2.6.7.(2)(i) of Division B of the Building Code. Therefore, the Agent maintained the air handling system serving the public corridor is considered to be part of a smoke control system for the high rise building.
The Agent further submitted, as permitted by Subclause 3.1.8.8A.(2)(a)(iii) of Division B of the Building Code, smoke dampers or a combination smoke and fire dampers are permitted to be waived for noncombustible branch ducts having a melting point above 760oC that penetrate a fire separation and are required to function as part of a smoke control system. The Agent confirmed the proposed branch ducts are noncombustible and have a melting point above 760oC. Further, the Agent confirmed the proposed air handling system complies with all other parts of Article 3.2.6.2., including MMAH Supplementary Standard SB-4.
Therefore, the Agent maintained the position that, as per Subclause 3.1.8.8A.(2)(a)(iii) of Division B of the Building Code, smoke dampers are not required to be provided at the air-transfer openings between the air-handling branch duct and the public corridor as the branch ducts are noncombustible and have a melting point of not less than 760oC. The Agent indicated that due to the required design of the air handling system in the residential public corridor, as outlined above, the lack of smoke dampers for the branch ducts in a continuous operating air duct system is not considered to lead to a significant spread of smoke from a fire within a suite into the public corridors.
4. Respondent’s Position
The Designate for the Respondent submitted that the Applicant’s mechanical drawing packages for each building did not include provisions for smoke dampers or combination smoke and fire dampers at the penetration from shafts to the public corridor at each floor level as required by Clause 3.1.8.7.(2)(a) of Division B of the Building Code.
According to the Designate, Sentence 3.1.8.7.(2) of Division B of the Building Code requires smoke dampers or combination smoke and fire dampers be installed in ducts penetrating the public corridors or any fire separation in a residential occupancy.
It is the position of the Designate that the Applicant’s proposed make-up air system for the corridor ventilation, which is also designed to be used to provide the required fresh air to each suite (via infiltration through door undercuts) and to common area rooms on lower levels, does not meet the design criteria for a required smoke control system as specified in the Building Code.
The Designate further submitted waiving the smoke dampers on the basis that a make-up air fan, which supplies air to a fire floor, is considered part of a required smoke control system with no measures in place to control the movement of smoke (such as having a dedicated exhaust), could result in possible unsafe conditions for building’s occupants during a fire emergency.
According to the Designate, although the requirement of Sentence 3.2.6.2.(5.1) of Division B of the Building Code is for the make-up air unit to not shut down automatically upon actuation of the fire alarm to maintain corridor pressurization, this measure does not make the system, as proposed, part of a required smoke control system for the building.
In the case of high-rise residential buildings, it is the Respondent’s position that a required smoke control system shall be specifically designed to be activated in a fire condition to remove smoke from the fire area and to control the smoke movement within the building taking into account stack effect through pressurization modeling, using established engineered measures such as those described in MMAH Supplementary Standard SB-4.
As such, according to the Designate, the proposed make-up air system does not meet the requirements of a smoke control system and, therefore, the requirement for smoke dampers cannot be waived.
5. Commission Ruling
It is the decision of the Building Code Commission that the proposal to waive the requirement for smoke dampers at the air-transfer opening locations of the residential public corridors of Building A/B and Building C/D, on the basis that the corridor make-up air system forms part of a smoke control system, provides sufficiency of compliance with Sentence 3.1.8.7.(2), Subclause 3.1.8.8A.(2)(a)(iii) and Sentence 3.2.6.2.(5.1) of Division B of the Building Code at 7950 Bathurst Street and 8 Beverley Glen Boulevard, Thornhill, Ontario.
6. Reasons
i) The Commission received evidence confirming that a switch will be provided in the central alarm and control facility to allow for firefighters’ operation of the make-up air unit, in accordance with Clause 3.2.6.7.(2)(i) of Division B of the Building Code. The Commission also received evidence confirming the make-up air unit will be provided with emergency power, in accordance with Clause 3.2.7.9.(1)(c) of Division B of the Building Code, to prevent the air-handling system from shutting down automatically upon actuation of the fire alarm to maintain corridor pressurization. Therefore, it is the Commission’s opinion that the proposed air-handling system as proposed sufficiently complies with Sentence 3.2.6.2.(5.1) of Division B of the Building Code.
ii) The Commission also heard that the proposed air handling system complies with all other parts of Article 3.2.6.2., including MMAH Supplementary Standard SB-4.
Furthermore, the Commission reviewed the proposed amendment with respect to Sentence 3.2.6.2.(5.1) of Division B of the Building Code, which states:
“Except as provided in Article 3.2.4.13. or where there is a conflict with other smoke control measures in the building, air handling systems used to provide make-up air to public corridors serving suites in a Group C major occupancy shall not shut down automatically upon activation of the fire alarm so as to maintain corridor pressurization.”
The rationale for the proposed change is that corridor pressurization units must remain on to resist or limit the movement of smoke in a fire emergency. The make-up air units are therefore intended to limit the possibility for smoke from a fire within a suite spreading to the public corridor resulting in possible delays or ineffectiveness in emergency response operations.
iii) The Commission received evidence that the branch ducts that penetrate fire separations are noncombustible and have a melting point above 760°C and that positive pressure will be maintained in the residential corridors to limit smoke movement in a fire emergency. Based on the evidence provided, it is the Commission’s opinion that the proposed air handling system sufficiently complies with the requirements for exemption provided by Subclause 3.1.8.8A(2)(a)(iii). As a result, the requirement for smoke dampers described in Sentence 3.1.8.7.(2) for noncombustible branch ductworks that penetrate the required fire separations at each floor level is permitted to be waived.
Dated at the City of Toronto this 15th day in the month of August in the year 2022 for application number B-2022-04.
Alison Orr, Chair Designate
Christina Kalt
Albert Schepers