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BCC Ruling No. 98-23-628

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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 61, as amended by O. Reg. 400/91, 158/93, 160/93, 383/94, 20/95 and 395/96 (the "Ontario Building Code").

AND IN THE MATTER OF an application by Mr. George Simeonoff, President-Manager, Everstrong Floors and Walls Ltd., 191 King St., Weston, Ontario for the resolution of a dispute with Mr. Agris Robeznieks, Chief Building Official, City of Mississauga, Ontario to determine whether the studio floor assembly above the garage, as constructed, with a concrete slab including an embedded hydronic heat radiation system but without insulation provides sufficiency of compliance with Articles and of the Ontario Building Code at 1497 Bancroft Drive, City of Mississauga, Ontario.


Mr. George Simeonoff, President-Manager
Everstrong Floors and Walls Ltd.
Weston, Ontario


Mr. Agris Robeznieks
Chief Building Official
City of Mississauga


Mr. Michael Lio (Chair)
Mr. Kenneth Peaker
Mr. Cliff Youdale


Toronto, Ontario


May 21, 1998


May 21, 1998


Mr. George Simeonoff, President-Manager
Everstrong Floors and Walls Ltd.
Weston, Ontario

The Applicant

Mr. Roger Hebert, Inspector, HVAC Systems
City of Mississauga, Ontario
The Respondent


  1. The Applicant

Mr. George Simeonoff, President-Manager, Everstrong Floors and Walls Ltd., has been issued an order to comply under the Building Code Act, 1992 to insulate a concrete floor assembly which separates a garage from a studio above thereby bringing the floor into conformity with Article of the Ontario Building Code at 1497 Bancroft Drive, Mississauga, Ontario.

  1. Description of Construction

The building in dispute is a two-storey, single-detached residential structure and is the home of Mr. and Mrs. Peter Miller. It has a building area of 306.7 m2 (3,300 ft2).

The concrete floor assembly in question separates an unheated double car garage from a studio above and is uninsulated. Several loops of hydronic piping are embedded in the underside of the subject floor assembly which provides a certain level of heat in the garage and heat that radiates throughout the floor. (The current owner contends that the average garage temperature is 12.8oC (55oF)). Within the studio space the concrete floor has been finished with tiles. The rest of the building is heated by a conventional forced air system.

The garage walls are constructed (from exterior to interior) of a stucco coating on 45 mm (1 3/4 in) precast concrete on 38 mm (1 1/2 in) rigid insulation on 9.5 mm (3/8 in) exterior plywood supported by 38 by 135 mm (2 by 6 in) wood framing studs fini shed with 13 mm (1/2 in) gypsum board. The garage has an automatic, steel door.

  1. Dispute

The issue at dispute between the Applicant and Respondent is whether the subject concrete floor assembly as constructed without insulation provides sufficiency with Articles and of the Ontario Building Code. Article sets out the general requirement that walls, floors and ceilings that separate heated space from non-heated space must be provided with insulation. Article, in particular Sentence (1), sets out the specific R values required for the various building elements exposed to unheated space. As Table 9.25.2.A. of Article stipulates, a floor, other than a slab-on-ground, is required to provide insulation of RSI 4.4 (R25).

Since the hydronic tubing on the underside of the concrete slab provides a certain amount of heat in the garage the Applicant considers the garage to be heated space. The municipality on the other hand considers the garage as unheated. As such, they believe that insulation should be installed to bring the disputed floor into conformity with the OBC.

There also appears to be a discrepancy involving the plan review and inspection of the building regarding hydronic heating system. It seems the house was given approval based on the conventional heating system with insulation on the underside of the garage ceiling slab. A separate application was made later for the hydronic heating system. The Applicant contended that the hydronic system substituted for the insulation. The municipality expected that the insulation would be installed along with the hydronic system.

  1. Provisions of the Ontario Building Code

Article Required Insulation

All walls, ceilings and floors separating heated space from unheated space, the exterior air or the exterior soil shall be provided with sufficient thermal insulation to prevent moisture condensation on their room side during the winter and to ensure comfortable conditions for the occupants.

Article Minimum Thermal Resistance

(1) Except as permitted in Sentences (2), (3) and (4) the minimum thermal resistance of insulation shall conform to Table 9.25.2.A.

  1. Applicant's Position

The Applicant submitted that the concrete floor slab should not be required to provide any insulation whatsoever. In his view, the hydronic heating system, which offers not only heating but also a level of insulation between heated and unheated spaces , provides sufficiency of compliance with Articles and Although the Applicant does not consider the garage to be heated space, he did indicate that its average annual temperature was 12.8oC (55oF). He argued this was primarily because of the hydronic heating system, which he also noted contributes to the heating in the studio above. The temperature in the studio above the garage is maintained at a comfortable 21.1 to 23.8oC (70 to 75oF). Further, the tiles in the studio are always appropriately warmed, he claimed.

In the Applicant's opinion, insulation is not necessary because the concrete slab is warm already. It is a source of heat itself, he argued, that does not need insulation. The hydronic heating system acts as a layer of insulation in that serves to mitigate the cooler temperatures of the garage with respect to the heated studio above.

The Applicant noted that the subject building was being constructed as a model to feature "Precast Concrete and Wood Composite Walls" and "Suspended Concrete Composite Floors" with hydronic heat radiators. This demonstration house was given approval by the municipality except for the hydronic system, which required a separate application. As the Applicant noted, hydronic systems are not found within the Code. To keep the projectmoving, it was decided to apply for a conventional forced air heating system. During construction, the Applicant proposed a revision to the heating plan to include the hydronic system. He indicated that nearly eight to ten months past before the municipality objected to the hydronic system and the lack of insulation. By this time the house had been sold and the current occupants were surprised to hear of the municipality's concerns. The Applicant provided a letter from the owners stating that they are very happy with the hydronic heating system.

For these reasons, the Applicant was of the opinion that the R25 insulation was not required on the underside of the garage ceiling.

  1. Chief Building Official's Position

The Respondent submitted that the subject floor assembly must be provided with R25 insulation as per Table 9.25.2.A. of the Ontario Building Code. In their view, the hydronic system is just a supplementary heating system designed only to temper cold floors. It is not a substitute heating system, they argued. As a result, in the Respondent's opinion the garage is unheated space. Since the garage in their view is not heated it follows then that insulation as per Table 9.25.2.A. is required. Further, they were clearly of the view that the hydronic system cannot act as a replacement to insulation.

Regarding the plans examination and inspection, the Respondent noted that while the hydronic system had been permitted, the requirement for insulation had never been waived. As well, the need for insulation as per the approved drawings was indicated to the contractor several times during construction.

Finally, the Respondent offered the Applicant an alternative method of complying with the provisions of the OBC. They stated that they would be willing to eliminate the insulation requirement if heat loss calculations were conducted on the garage and an approved heating system be designed and provided in the garage that would satisfy the heat loss conditions. In effect, the Applicant would be required to make the garage truly heated space, thus eliminating the need for insulation.

  1. Commission Ruling

It is the decision of the Building Code Commission that the garage ceiling demonstrates sufficiency of compliance with the requirements of the Building Code.

  1. Reasons

1)A number of measures have been installed that provide additional energy savings including:

a)RSI 1.76 (R7.5) insulation in the garage walls.

b)RSI 4.84 (R27.5) insulation in the house walls.

c)A high efficiency furnace.

d)A heat recovery ventilator.

2)Insulating the garage ceiling is impractical given the intent of the in-floor hydronic heating system to keep the floor above warm and to supply low grade heat to the garage.

3)The garage ceiling slab is heated with a heating system independent from that of the house.

Dated at Toronto this 21st day in the month of May in the year 1998 for application number 1998-22

Mr. Michael Lio, Chair

Mr. Kenneth Peaker

Mr. Cliff Youdale