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BCC Ruling No. 98-21-626

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IN THE MATTER OF Subsection 24 (1) of the Building Code Act, 1992.

AND IN THE MATTER OF Articles, and of Regulation 403, as amended by O. Reg. 22/98, 102/98, and 122/98 (the "Ontario Building Code").

AND IN THE MATTER OF an application by Mr. Keith McEwen, President, Keith McEwen Associated Ltd, Guelph, Ontario for the resolution of a dispute with Mr. Bruce Poole, Chief Building Official, City of Guelph, Ontario to determine whether the recently constructed addition of an air-supported structure to an existing single storey office building is required to install a standpipe and hose system, to provide a 1 hour fire resistance-rating on the mezzanine, and to separate the new and existing portions of the building also by a 1 hour rating in accordance with Articles, and respectively of the Ontario Building Code at the Guelph Sports Dome, 550 Imperial Road North, Guelph, Ontario.


Mr. Keith McEwen, President
Keith McEwen Associated Ltd.
Guelph, Ontario


Mr. Bruce Poole
Chief Building Official
City of Guelph


Mr. Roy Philippe (Chair)
Ms. Susan Friedrich
Mr. Ross Thomson


Toronto, Ontario


May 6, 1998


May 6, 1998


Mr. Jonathan Rubes, President, Leber Rubes Inc.
Toronto, Ontario

Agent for the Applicant

Mr. Paul Moore, Permit and Zoning Administrator
City of Guelph
For the Respondent


  1. The Applicant

Mr. Keith McEwen, President, Keith McEwen Associated Ltd. received a building permit under the Building Code Act, 1992 to construct an air-supported addition to an existing one storey office building at the Guelph Sports Dome, 550 Imperial Road North, Guelph, Ontario.

  1. Description of Construction

The Applicant recently constructed a new air-supported structure, known as the Guelph Sports Dome, as an addition to an existing one storey office building. The addition is intended to accommodate a two-tiered indoor golf range and three soccer fields. The enlarged building, including addition, has a total building area of 3,132.4 m2 and is one storey in building height, with the highest point measured at 15.24 metres. The occupant load is approximately 160 persons.

The air-supported, fabric-covered, sports dome has a building area of 3,076 m2. Also included in the recent addition is a 53.5 m2 air-lock storage area and a 2.9 m2 air-lock entrance. A 1 hour fire separation was provided where the air-supported addition connects to the existing office building. The addition is constructed of combustible construction. Fire department access is provided on the north side of the addition.

The addition is classified as a Group A, Division 2 - sports/entertainment assembly occupancy. As currently built, the air-supported structure is not equipped with a fire alarm system, a sprinkler system, nor a standpipe and hose system.

The existing office building is also constructed of combustible construction. It has a building area of 187.4 m2 and has fire department access on its east side. It is classified as a Group D -Business occupancy

The permit application for the air-supported structure was made under the requirements of the 1997 OBC.

  1. Dispute

There are three issues at dispute between the Applicant and Respondent. The first issue is whether the air-supported structure should be equipped with a standpipe and hose system as per Sentence This provision stipulates that a standpipe and hose system must be installed in a single storey building containing an assembly occupancy that is 2,500 m2 or larger. Sentence does allow air-supported structures an exemption from this requirement.

The second issue is whether the two-tiered golf driving range, which represents a mezzanineapproximately 4.6 % of the floor area, must be provided with a 1 hour fire-resistance rating. Sentence of the OBC requires that interior mezzanines within air-supported structures must meet the construction requirements found in Subsection 3.2.2., specifically Article This provision states that the mezzanine must be constructed of noncombustible construction, including its supporting members, and have a fire-resistance rating of at least one hour. The noncombustible requirements of this provision also applies to the air-lock facilities, the storage and entrance areas.

The third issue is whether the air-lock vehicle/storage and entrance areas can be attached to the main portion of the air-supported structure without providing a 1 hour fire separation at the connection. Sentence permits an air-supported structure to be connected to another building if the building is less than 200 m2 and a 1 hour fire separation is provided at the connection.

  1. Provisions of the Ontario Building Code

Sentence Required

(1) Except as provided in Sentences (4) to (7), a standpipe system shall be installed in every building that

a) is more than 3 storeys in building height,

b)is more than 14 m (45 ft 11 in) high measured between grade and the ceiling of the top storey, or

c)is not more than 14 m (45 ft) 11 in) high measured between grade and the ceiling of the top storey but has a building area exceeding the area shown in Table for the applicable building height if the building is not sprinklered.

Sentence Construction

(5) Interior construction contained within air-supported structures must meet the construction requirements of Articles to

Sentence to Adjacent Building

(4) An air-supported structure is permitted to be attached to another building provided the building to which it is attached.

a)has a building area not more than 200 m (2,150 ft ).

b)conforms to the requirements of other Parts of the Code based on the building area of the attached building, and

c)is sprinklered or separated from the air-supported structure by a fire separation having a fire-resistance rating of not less than 1 h.

  1. Applicant's Position

By way of general comments, the Applicant indicated that the design of the subject air-supported structure complies with all other relevant provisions in Part 3 of the OBC, save for the disputed areas. This includes the clearance from adjacent properties and flammable material and vegetation, structural design and flame-resistance. The Applicant noted that the fabric covering the proposed addition meets the CAN/ULC S-109-M standard and is in fact self-extinguishing, thereby unable to support combustion.

The Applicant also noted that the fire separation between the addition and the existing office area is not at issue since, as a separate building, they concur that a 1 hour fire separation is required. Further, the provision of egress from the sports facility far exceeds the Code requirements, the Applicant contended. This is due to the fact that the exits provided are sufficient for 650 people, although the occupant load is only 160 persons (as calculated by the Respondent) and that the 30 metre travel distance requirements are easily met. The evacuation time would therefore be faster than that required in the Code. Also noted by the Applicant was that there is little visual obstruction in the building that could hide potentially dangerous situations and that the sports facility has on-site staff to supervise in case of an emergency.

Moreover, the life safety of the building is currently being enhanced by the incorporation of an early warning system to detect sudden changes in pressure. This is being done by linking pressure gauges into the 24 hour monitored security system. This is in addition to the already in place emergency power system.

Regarding the first issue, the Applicant submitted that the provision of a standpipe and hose system in the air-supported building would be of questionable value to the responding fire department. They note that the manufacturer of the subject structure recommends that fire fighting activities occur from the exterior using street hydrants. In the case of the subject facility, a hydrant is located directly across the municipal street. The Applicant also noted that the addition has very little combustible load, virtually no sources of ignition, and is supplied with several portable fire extinguishers

On the issue of the construction requirements for the mezzanine, the Applicant recognized that Sentence exempts air-supported structures from most of the construction requirements found in Subsection 3.2.2., with the exception of interior construction, which includes the mezzanine. The Applicant, however, argued that the as built mezzanine provides an acceptable level of life safety without providing the 1 hour fire resistance rating. They described the construction of the mezzanine as being primarily of noncombustible elements. (The construction of the mezzanine is as follows; 25 oz astro grass is laid on 5/8 in plywood on noncombustible insulation on a 1 in steel deck which is supported by a structure of structural steel.) They also argued that the construction of the mezzanine does not leave the combustible exposed. In their view, this represents a less hazardous situation than combustible finished flooring which is allowed in noncombustible construction, or concealed spaces created by combustible nailing.

Further, the Applicant pointed out that the mezzanine is a stand alone structure that is open on all four sides. This allows excellent visibility of the sports facility thus allowing occupants ample warning time to evacuate. Also, with four open sides occupants would not be trapped on the mezzanine. While the Respondents have assigned the mezzanine an occupant load of 60, in the Applicant's view, since there are only 11 driving stations the actual load is and will be much lower.

The Applicants indicated that previous Building Code Commission have recognized similar construction and occupant use for mezzanines. They discussed as well that the mezzanine complies with the OBC regarding egress, guards and rails, emergency lighting and structural design.

Regarding the connection to the adjacent vehicle/storage air-lock and entrance air-lock, the Applicant is of the opinion that these areas are not separate buildings, but are instead subsidiary elements, part of the overall air-supported structure. It follows, they argued, that Sentence with its 1 hour fire separation requirements does not apply. As the Applicant noted the vehicle air-lock is provided so that a vehicle can enter the building or be stored with other material that relates to the operation of the sports facility while still maintaining operating pressure and the entrance enclosure serves to protect the revolving door lock from the weather. These two areas have no occupancy in and of themselves, they are ancillary to the main area of the sports dome.

The Applicant did not view these connections as part of the interior construction that is required to be noncombustible. Rather, they considered the subject connections as part of the building that is allowed to be exempt from the construction requirements found in Subsection 3.2.3. Besides, construction of an internal fire separation at the vehicle air-lock would provide minimal benefit since the exterior fabric walls of the sports dome area meet those of the vehicle air-lock area without separation. Nevertheless, the Applicant stated that they were willing to finish the interior of the vehicle air-lock with gypsum wallboard.

For the above described reasons, the Applicant is of the opinion that the proposed design of the air-supported structure provides sufficiency of compliance with the relevant provisions of the Building Code.

  1. Chief Building Official's Position

The Respondent submitted that Subsection 3.2.9. of the OBC is clear in its requirement of a standpipe and hose system. As they note, the building has an assembly occupancy, is a single storey and is greater than 2,500 m2, which according to Sentence means that a standpipe and hose system is required.

Concerning the mezzanine, the Respondent cited Sentence which refers to the construction requirements of Subsection 3.2.2., which for the subject building means that the mezzanine must be built with noncombustible construction and have a 1 hour fire-resistance rating for the mezzanine and its structural members.

In the Respondent's view, the two ancillary areas, namely the vehicle air-lock and the entrance air-lock, should be treated as separate buildings and must therefore provide a 1 hour fire separation between these two areas and the sports dome area. They argued that the air-lock areas are more appropriately viewed as additions to the sports dome which are both combustible construction and are built with different materials than the sports dome area. The Respondent noted that the air-lock areas could opt for sprinklering as an alternative to providing the 1 hour fire separation.

As a result of the above discussion, the respondent did not believe that the sports dome, as constructed, provides sufficiency of compliance with the applicable OBC provisions.

  1. Commission Ruling

It is the decision of the Building Code Commission that the air supported structure connected to the single storey office building provides sufficiency of compliance with Articles,, and of the 1997 Building Code provided that:

i)The occupant load is limited to 160 persons and a sign limiting occupancy is posted in accordance with Sentence of the Building Code.

ii)The interior of the vehicle air-lock is protected with drywall material or equivalent to provide a 45 minute fire-resistance rating and the over head door between the vehicle air-lock and the air-supported structure is of noncombustible construction.

iii)Monitored smoke detection devices are installed within the structure or within the air handling system and connected to the existing security system.

  1. Reasons

i)This structure is in the same location and is the same approximate size as former air-supported structures on the site and is using the same foundation base.

ii)The main entrance and air-lock will be protected combustible construction having a 3/4 hour fire-resistance rating.

iii)The mezzanine structure is noncombustible.

iv)The building occupant load is limited to 160 persons.

v)Early warning detection is installed and connected to a central monitoring agency.

Dated at Toronto this 6th day in the month of May in the year 1998 for application number 1998-17.

Mr. Roy Philippe, Chair

Ms. Susan Friedrich

Mr. Ross Thomson