Ruling No.: 19-09-1529
Application No.: B-2019-01
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 Articles 9.8.3.1., 9.8.3.2., 9.8.4.3. and 9.8.4.5 of Regulation 332/12, as amended, (the “Building Code”).
AND IN THE MATTER OF an application by John Wood, for the resolution of a dispute with George Kotsifas, Chief Building Official to determine whether the proposed design of the stairs serving a 2 storey residential dwelling, provides sufficiency of compliance with Articles 9.8.3.1., 9.8.3.2., 9.8.4.3. and 9.8.4.5 of Division B of the Building Code at 1535 Gloucester, London, Ontario.
APPLICANT John Wood
Brysonwood Homes
London, Ontario
RESPONDENT George Kotsifas
Chief Building Official
City of London
London, Ontario
PANEL Stephen Wong, Chair
Rick Mori
Andrew Steen
PLACE City of Toronto, Ontario
DATE OF HEARING March 21, 2019
DATE OF RULING June 18, 2019
APPEARANCES Carl Roes
President
Roes Stair Corp.
Mount Brydges, Ontario
Agent for the Applicant
Peter Kokkoros
Deputy Chief Building Official
Development & Compliance Services – Building Division
City of London, Ontario
Designate for the Respondent
Theo Groenweg
Manager of Inspections
City of London, Ontario
Designate for the Respondent
RULING
1. Particulars of Dispute
The Applicant has applied for a building permit under the Building Code Act, 1992, to construct a new residential dwelling with 2 interior stairs at 1535 Gloucester Road, London, Ontario.
The subject building is a two storey residential building comprised of combustible construction having a building area of 464.68 m².
In dispute is the design of the two as-built stairs in the subject dwelling: one serving the basement and main floor and the other stair serving the main floor and second floor of the house. The as-built stairs having an elliptical shape and tapered treads are the subject of dispute. More specifically, the dispute centres on whether the design of the stairs provides sufficiency of compliance with Articles 9.8.3.1., 9.8.3.2., 9.8.4.3. and 9.8.4.5 of Division B of the Building Code.
The hearing for this application was held on March 21, 2019. After the hearing, the Commission determined that additional information was required from both the Applicant and Respondent to enable the panel to come to a decision regarding the above noted dispute. Therefore, the hearing was adjourned. Once the requested information was received from both parties, the Commission panel deliberated and made their decision on June 18, 2019.
2. Provisions of the Building Code in Dispute
9.8.3.1. Straight and Curved Runs in Stairs
(1) Except as provided in Sentence (2), stairs shall consist of,
(a) straight-runs, or
(b) curved-runs.
(2) Stairs within dwelling units shall consist of,
(a) straight-runs,
(b) curved-runs,
(c) straight-runs with winders, or
(d) straight-runs with curved-runs.
9.8.3.2. Minimum Number of Risers
(1) Except for stairs within a dwelling unit, at least three risers shall be provided in interior flights.
9.8.4.3. Dimensions for Angled Treads
(1) Angled treads in required exit stairs shall conform to the requirements in Article 3.4.6.9.
(2) Except as provided in Article 9.8.4.5., angled treads in other than required exit stairs shall have an average run, which is measured as the horizontal nosing-to-nosing distance, of not less than 200 mm and a minimum run of 150 mm.
(3) The depth of an angled tread shall be not less than its run, measured as the horizontal nosing-to-nosing distance, at any point and not more than its run at any point plus 25 mm.
9.8.4.5. Winders (See Appendix A.)
(1) Stairs within dwelling units are permitted to contain winders that converge to a centre point provided,
(a) the winders turn through an angle of not more than 90°,
(b) individual treads turn through an angle of not less than 30° or not more than 45°, and
(c) adjacent winders turn through the same angle.
(2) Where more than one set of winders described in Sentence (1) is provided in a single stairway between adjacent floor levels, such winders shall be separated in plan by at least
1200 mm.
3. Appendix Note A-9.8.4. Step Dimensions
The Code distinguishes three principal types of stair treads and uses the following terminology to describe them:
rectangular treads are found in straight-run flights;
angled treads are found in curved flights;
winders are a special type of angled tread described in Appendix Note A-9.8.4.5. See Figure A-9.8.4.A.
Figure A-9.8.4.A. Types of Treads
Articles 9.8.4.1. to 9.8.4.6. specify various dimensional limits for steps. Figure A-9.8.4.B illustrates the elements of a step and how these are to be measured.
Figure A-9.8.4.B. Elements of Steps and their Measurement
4. Appendix Note A-9.8.4.5. Winders.
The safest method of incorporating a change in the direction of a stair is to use a landing. Within a dwelling unit, however, where occupants are familiar with their environment, winders are an acceptable method of reducing the amount of floor area devoted to the stair and have not been shown to be more hazardous than a straight run of steps. Nevertheless, care is required to ensure that winders are as safe as possible. Experience has shown that 30° winders are the best compromise and require the least change in the natural gait of the stair user; 45° winders are also acceptable, as they are wider. The Code permits winders to turn through any angle between 30° and 45°, inclusive. This allows winder-type stairs to change direction through any angle between 30° (1 winder) and 90° (2 or 3 winders).
5. Applicant’s Position
The Agent for the Applicant submitted the subject as-installed stairs are curved stairs having an elliptical shape and that the design of the stairs’ treads can be best described as ‘tapered treads’ as defined by the 2015 National Building Code.
The Agent submitted that Ontario’s Building Code currently does not address ‘tapered treads’ and does not set out the dimensions for compliance. The Agent submitted that it was his opinion, having participated in the National Research Council’s code development committee for the 2015 National Building Code, that Ontario would soon adopt the same provisions related to tapered treads.
The Agent explained that it is not a requirement of the Building Code that all stair treads be configured with the same shape, but rather that they turn in the same direction. He advised that although tapered treads are found mostly in curved flights, the Building Code does not specify that they must be part of a curved stair. Therefore, he maintained, as there is no limit placed on the maximum radius that a curved stair might have, a stair with a large enough radius could have virtually straight runs.
The Agent submitted that that Article 9.8.4.3. of the Building Code requires a minimum run of 150 mm at the narrow end, and that the as-built stairs have a minimum of 197 mm. He further added that the average run of the subject stairs is 240 mm, whereas the Building Code requires a minimum of 200mm. Therefore, the Agent maintained that the as-built stairs meet the requirements of the Building Code.
The Agent explained that the 2015 National Building Code recognizes that the run is permitted to deviate in certain circumstances, and in some cases the run of the bottom treads may be allowed to exceed the run of treads further up. The Agent submitted that construction tolerances are permitted by the Building Code and further, residents of the home are familiar with the stairs and have had no issue or concerns. The Agent maintained that in his professional opinion, the small deviation in the run of the lower part of the stair does not pose a significant impediment or hazard to the functionally of the stair.
In response to questions, the Agent stated he’d be willing to install a handrail on the wall side of the stairs as an additional safety measure.
6. Respondent’s Position
The Designate for the Respondent submitted that the as-built stairs were not seen by the municipality until final inspection took place for occupancy and it was at that time that it was discovered that the stairs were not built in accordance with the approved drawings and further, that they were not built in compliance with the Building Code.
The Designate explained that the subject stairs are not standard stairs but are somewhat out of the ordinary. The Designate indicated that the treads in the subject stairs are not uniform and that their dimensions and angles vary. The Designate maintained that in a curved stair, the treads should show uniformity. He further submitted that the as-built stair does not meet the Building Code requirements and dimensions for angled treads in a curved stair.
The Designate submitted that based on the design and configuration of the as-built stairs, the stairs do not comply with Clause 9.8.3.1.(2)(d) of Division B of the Building Code in that they are not considered stairs consisting of straight-runs with curved runs. Specifically, the Designate argued, the as-constructed stair does not have a straight run leading into a curved portion.
The Designate indicated that Sentence 3.4.6.9.(2) of the Building Code requires a curved stair to have a handrail on both sides, a minimum tread depth of 240 mm, and an inside radius not less than twice the width of the stair. The Designate maintained that the subject stairs do not meet these requirements.
The Designate cited Sentence 9.8.4.3.(1) of the Building Code as also being in dispute as the subject stairs having angled treads are part of an exit stair, as the stairs serve as exits from the second floor and the basement of the dwelling to the main floor.
The Designate submitted that the variation in the treads with respect to curvature and angles could pose a safety hazard for those ascending and descending the stairs.
The Designate maintained that it was the municipality’s position that the as-built stairs do not comply with the requirements of the Building Code.
7. Commission Ruling
It is the decision of the Building Code Commission that the proposed design of the stairs serving a 2 storey residential dwelling, provides sufficiency of compliance with Article 9.8.3.1. and 9.8.4.3. of Division B of the Building Code at 1535 Gloucester, London, Ontario on condition that:
a) a handrail is constructed on the wall side of the 2 stairs and,
b) the nosing overhang is reduced to meet the requirement of Clause of 9.8.4.6.(1)(b) of Division B of the Building Code.
8. Reasons
i) Sentence 9.8.3.1.(2) of Division B of the Building Code indicates the various stair configurations that are permitted to be installed in a dwelling unit.
Based on the evidence and testimony presented including photos and plan drawings, the Commission considers the subject as-built elliptical shaped stair to be a stair consisting of curved runs as permitted by Clause 9.8.3.1.(2)(b).
ii) Article 9.8.3.2. of Division B of the Building Code states, “Except for stairs within a dwelling unit, at least three risers shall be provided in interior flights”. The Commission heard evidence and testimony that the subject stairs are located within a dwelling unit. Therefore, it is the Commission’s opinion that Article 9.8.3.2. is not applicable in this case.
iii) Article 9.8.4.3. of Division B of the Building Code sets out the dimensions that a stair constructed with angled treads needs to meet.
Although not forming part of the Building Code, the Commission recognizes that the Appendix Notes are referred to by Building Code users for explanatory purposes.
Appendix Note A-9.8.4., regarding step dimensions states:
The Code distinguishes three principal types of stair treads and uses the following terminology to describe them:
rectangular treads are found in straight-run flights;
angled treads are found in curved flights;
winders are a special type of angled tread described in Appendix Note A-9.8.4.5. See Figure A-9.8.4.A.
Figure A-9.8.4.A. Types of Treads
As per Appendix A-9.8.4. and Figure A-9.8.4.A., the Commission notes that angled treads are found in curved flights. Based on a review of the floor plans and sections of the two as- built stairs with dimensions shown, it is the Commission’s opinion that the as-installed stairs are a type of curved stair having angled treads and therefore, Article 9.8.4.3. is applicable.
iv) Sentence 9.8.4.3.(1) of Division B of the Building Code states, “Angled treads in required exit stairs shall conform to the requirements in Article 3.4.6.9.” The Commission heard evidence that the subject as-built stairs in the residential dwelling are not exit stairs and therefore, Sentence 9.8.4.3.(1) is not applicable in this case.
Sentence 9.8.4.3.(2) states, “Except as provided in Article 9.8.4.5., angled treads in other than required exit stairs shall have an average run, which is measured as the horizontal nosing-to-nosing distance, of not less than 200 mm and a minimum run of 150 mm.
Based on the supplementary information provided by the Applicant in response to the Commission’s questions upon the adjournment of the May 9th hearing, the Commission is of the opinion that the as-built stairs achieve sufficiency of compliance with Sentence 9.8.4.3.(2).
Sentence 9.8.4.3.(3) states, “The depth of an angled tread shall be not less than its run, measured as the horizontal nosing-to-nosing distance, at any point and not more than its run at any point plus 25 mm.
The Commission is of the opinion that once the condition b) as stipulated above is satisfied, sufficiency of compliance with Sentence 9.8.4.3.(3) is achieved.
v) Article 9.8.4.5. of Division B of the Building Code sets out the requirements for winders. The Commission heard testimony that both parties agree the subject stairs are not winders and therefore, it is the Commission opinion that Article 9.8.4.5. of the Building Code is not in dispute.
vi) Due to the unique configuration of the subject stairs, it is the Commission’ opinion that the installation of a handrail on the wall side of the stair, as stipulated in condition a) provides an additional level of safety.
Dated at the City of Toronto this18th day in the month of June in the year 2019 for application number B 2019-01.
Stephen Wong, Chair
Rick Mori
Andrew Steen