Arbitrator rules that compliance with kindergarten class size regulations is required only as of determination date

December 5, 2019 | Seann D. McAleese, Stephanie Tassopoulos

A recent arbitral decision clarified the requirements that must be satisfied in order for a school board to comply with regulations in Ontario regarding kindergarten class sizes. The Elementary Teachers’ Federation of Ontario (the “ETFO”) filed a grievance claiming that the Bluewater District School Board (the “Board”) violated a regulation under Ontario’s Education Act when an influx of new students caused class sizes to exceed the stipulated class size limits; the arbitrator held that there was no such violation, and dismissed the grievance.

Factual Background

Ontario Regulation 132/12 (“Regulation 132/12”) sets out the legislative scheme by which class sizes are governed. This Regulation requires school boards to choose a date between September 1 and September 30 in a given school year as the date on which that school board’s class sizes will be determined; this date is referred to in the arbitrator’s reasons as the “Determination Date.”

Prior to 2017, the only requirement with respect to the size of kindergarten classes was the average class size across the school board. This led to situations where the number of students in certain kindergarten classes was very high, while the number of students in kindergarten classes at other schools was very low, but the board was still technically in compliance with the required school board-wide average class size.

The ETFO and the Board had a collective agreement in place which was scheduled to expire on August 31, 2017. Prior to the expiry of this agreement, the ETFO and the Ontario government entered into negotiations with respect to the potential extension of the collective agreement for another two years. One of the ETFO’s objectives during these negotiations was to obtain, in addition to the mandated board-wide average class size, a legislated maximum limit on kindergarten class sizes.

On February 2, 2017, the ETFO and the government entered into an Extension Agreement, extending the term of their collective agreement. Pursuant to this Agreement, the government enacted amendments to Regulation 132/12 to add the following new provisions:

  • Section 2.1(1) states that the class size limit for a class of only junior kindergarten and  kindergarten students is 29. In the 2017-2018 school year, this limit was 30 students.
  • Section 2.1(2) states that in each year, 10% or fewer kindergarten classes may exceed the class size limit, but may not exceed 32 students, in a number of listed circumstances. This is referred to as the kindergarten class size limit “Flex Factor”.
  • Section 11(3) requires a school board to submit a report by October 31st of the school year to justify their reasoning for relying on the “Flex Factor” to increase a kindergarten class size.

The parties agreed that with respect to the board-wide class average, a School Board only had to comply with the mandated class average on the Determination Date; if the average class size rose after that date, the Board would not be in violation of the Regulation.

However, the parties disagreed on the interpretation of the timing requirements for the newly added maximum class size limits. The ETFO submitted that the maximum size limit contained in section 2.1(1) of the Regulation could not be exceeded on the Determination Date, nor throughout the rest of the school year. The Board submitted that the maximum size limit applied only on the Determination Date, and that, like with the average class size, any increase in the class size after the Determination Date was not a violation of the Regulation.

In the 2017-2018 school year, the Board complied with the permitted class average of 26 and per class maximum of 30 students as of their selected Determination Date. This grievance arose because in February of that school year, two kindergarten classes in a school operated by the Board grew to 35 and 37 students, thereby exceeding the maximum class size limit.


Applying the well-established approach to statutory interpretation to the language of the Regulation, Arbitrator Nyman dismissed the ETFO’s grievance. He ruled that Regulation 132/12 only requires school boards to comply with mandated kindergarten class size limits on the Determination Date, and not throughout the duration of the school year[1].

Arbitrator Nyman began by noting that the Regulation was “worded awkwardly”.[2] In interpreting section 3(1) of the Regulation which establishes the requirement for school boards to select a Determination Date, the arbitrator found that this provision is not limited specifically to average class sizes or only kindergarten classes; rather, it sets a date on which all size determinations for all elementary classes are to be made. The arbitrator also drew on similarities in language and structure of the provisions relating to kindergarten and primary grade class sizes in support of the conclusion that all class sizes are to be determined only at the Determination Date.

Finally, the Arbitrator stated that his decision was reinforced by two factors: i) there was a long history of class size limits being determined as of a fixed day, and ii) the requirement in s.11(3) that class sizes be reported on October 31st with justification for accessing the Flex Factor would be of little use if the per class maximum limit was to remain in place for the entirety of the school year.

This decision provides clarity to school boards throughout Ontario that the key date for compliance with the kindergarten class size limits, both with respect to the board-wide average and the per class maximum, is the Determination Date. As such, schools which experience an influx of new students, and a corresponding increase in class sizes, after this Determination Date are not in violation of the Regulation.

[1] Ontario Secondary School Teachers’ Federation v. The Crown in Right of Ontario, 2019 CanLII 84798.

[2] Para 54.


This publication is provided as an information service and may include items reported from other sources. We do not warrant its accuracy. This information is not meant as legal opinion or advice.

Miller Thomson LLP uses your contact information to send you information electronically on legal topics, seminars, and firm events that may be of interest to you. If you have any questions about our information practices or obligations under Canada's anti-spam laws, please contact us at

© 2022 Miller Thomson LLP. This publication may be reproduced and distributed in its entirety provided no alterations are made to the form or content. Any other form of reproduction or distribution requires the prior written consent of Miller Thomson LLP which may be requested by contacting