How high does a guard on a house stair have to be?
Seven texts since 1998. The code sets the flight and the landing separately, and for eight years they were 170 mm apart.
Retrieved 3 September 2026. Every text below is rendered from our corpus by the components the product ships, except the 2024 one, which is quoted.
What is the minimum height of a guard on a stair inside a house in Ontario?
The answer depends on the date, and on which part of the stair you are asking about. A flight is the sloped run of steps. A landing is the flat platform at the top, at the foot, or between two flights. The code has set them apart and they have at times varied. For a time starting in 2022, spiral stairs were handled separately.
| In force | Flight | Landing | Spiral stair | Notes |
|---|---|---|---|---|
| 6 Apr 1998 to 30 Dec 2006 |
800 mm | 900 mm | 800 mm | The only text that allows 800 mm. 1998 |
| 31 Dec 2006 to 31 Dec 2013 |
900 mm | 900 mm | 900 mm | The flight rises 100 mm, and the rule falls under a different article. 2006 |
| 1 Jan 2014 to 31 Dec 2021 |
900 mm | 1 070 mm | 900 mm | A new sentence raises the landing to 1 070 mm. 2014 |
| 1 Jan 2022 to 31 Dec 2024 |
900 mm | 900 mm | 1 070 mm | The landing drops back to 900 mm, and spiral stairs go the other way. 2022 |
| 1 Jan 2025 to today |
900 mm | 900 mm | 900 mm | A new code, and the spiral-stair exception does not come with it. 2025 |
A building is governed by the code in force when its permit was issued, so the answer varies by date.
Note, we are assuming the stairs are not exit stairs, so their 920 mm rule does not apply.
Below are the actual provision versions each table row comes from. The oldest version is shown whole. After follow the amendments, with their diffs highlighted (and unchanged words dimmed).
1998: 800 mm
OBC1997 came into force on 6 April 1998. Guard height is Article 9.8.8.2., and sentence (4) answers our question. It sets 800 mm for indoor stairs in general and 900 mm above their landings.
OBC 1997 — 9.8.8.2. Height of Guards
In force from 6 April 1998 to 30 December 2006.
Building the citations…
(1) This Regulation comes into force on March 16, 1998. 48/97
Read directly from the regulation's own commencement section.
O. Reg. 403/97 · commencement 12.3.1.1.(1)
This version stayed in force until the next edition replaced it. What follows is that edition’s base regulation’s commencement — the takeover that ended this one.
(1) This Regulation comes into force on December 31, 2006.
Read directly from the regulation's own commencement section.
O. Reg. 350/06 · commencement 2.2.1.1(1)
The band above the text is how CodeChronicle shows when the provision version was in force and what regulation changed it.
31 December 2006: the flight rises, and the article shifts
OBC2006 rewrites the article. Article 9.8.8.2. still exists, and it is now Loads on Guards. Our rule now falls under Article 9.8.8.3. and the 800 mm allowance is dropped. Sentence (2) now covers every guard within a dwelling unit, landings included.
v0 O. Reg. 403/97 · base
Earlier · 1998-04-06(1) Except as provided in Sentences (2) to (4), all guards, including
those for balconies, shall be at least 1 070 mm high.
(2) Guards for porches, decks, landings and balconies are permitted
to be a minimum of 900 mm high where
(a) the walking surface of the porch, deck, landing or balcony
served by the guard is not more than 1 800 mm above the
finished ground level, and
(b) the porch, deck, landing or balcony serves not more than one
dwelling unit.
(3) Except as provided in Sentence (4), guards for stairs shall be not
less than 900 mm high measured vertically from a line drawn through
the outside edges of the stair nosings, and 1 070 mm high at landings.
(4) Guards for stairs within dwelling units and stairs serving not
more than one dwelling unit shall be not less than 800 mm measured
vertically above a line drawn through the outside edges of stair nosings,
and not less than 900 mm above landings.
(5) All required guards within dwelling units other than those
described in Sentence (4) shall be not less than 900 mm high.
v0 O. Reg. 350/06 · base
Later · 2006-12-31(1) Except as provided in Sentences (2) to (4), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) The height of guards for flights of steps shall be measured vertically from a line drawn through the leading edge of the treads served by the guard.
1 January 2010: the article changed, but not our answer
This amendment updates one sentence, clarifying that you measure from the top of the guard. Guard heights themselves are untouched.
v0 O. Reg. 350/06 · base
Earlier · 2006-12-31(1) Except as provided in Sentences (2) to (4), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) The height of guards for flights of steps shall be measured vertically from a line drawn through the leading edge of the treads served by the guard.
v1 O. Reg. 503/09
Later · 2010-01-01(1) Except as provided in Sentences (2) to (4), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) The height of guards for flights of steps shall be measured vertically from from the top of the guard to a line drawn through the leading edge of the treads served by the guard.
1 January 2014: the landing goes to 1 070 mm
OBC2012 changes several things, but relevant to our question is sentence (5) which says guards shall be not less than (a) 920 mm for required exit stairs [not applicable to our case inside a house], and (b) 1 070 mm around landings.
v1 O. Reg. 503/09
Earlier · 2010-01-01(1) Except as provided in Sentences (2) to (4), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) The height of guards for flights of steps shall be measured vertically from from the top of the guard to a line drawn through the leading edge of the treads served by the guard.
v0 O. Reg. 332/12 · base
Later · 2014-01-01(1) Except as provided in Sentences (2) to (6), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) Except as provided in Sentence (6), the height of guards shall be not less than,
(a) 920 mm for required exit stairs, and
(b) 1 070 mm around landings.
(6) The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1 500 mm.
(7) The height of guards for stairs and landings shall be measured vertically from the top of the guard to,
(a) a straight line drawn tangent to the tread nosings of the stair, or
(b) the surface of the landing.
1 July 2017: outside only
Only one sentence changes, and it's about exterior guards; "serving not more than one dwelling unit" becomes "serving a house or an individual dwelling unit". Not relevant to this question.
v0 O. Reg. 332/12 · base
Earlier · 2014-01-01(1) Except as provided in Sentences (2) to (6), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) Except as provided in Sentence (6), the height of guards shall be not less than,
(a) 920 mm for required exit stairs, and
(b) 1 070 mm around landings.
(6) The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1 500 mm.
(7) The height of guards for stairs and landings shall be measured vertically from the top of the guard to,
(a) a straight line drawn tangent to the tread nosings of the stair, or
(b) the surface of the landing.
v1 O. Reg. 139/17
Later · 2017-07-01(1) Except as provided in Sentences (2) to (6), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving a house or an individual dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) Except as provided in Sentence (6), the height of guards shall be not less than,
(a) 920 mm for required exit stairs, and
(b) 1 070 mm around landings.
(6) The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1 500 mm.
(7) The height of guards for stairs and landings shall be measured vertically from the top of the guard to,
(a) a straight line drawn tangent to the tread nosings of the stair, or
(b) the surface of the landing.
1 January 2022: landings drop back to 900 mm
Sentence (5) is revoked. No exception sets a landing height any more, so a landing inside a house falls to sentence (2) at 900 mm.
Words are also added to sentence (2): guards within dwelling units are 900 mm, other than guards serving spiral stairs. So, spiral stairs fall back to the general 1 070 mm requirement from sentence (1).
v1 O. Reg. 139/17
Earlier · 2017-07-01(1) Except as provided in Sentences (2) to (6), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units shall be not less than 900 mm high.
(3) Exterior guards serving a house or an individual dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights of steps, except in required exit stairs, shall be not less than 900 mm high.
(5) Except as provided in Sentence (6), the height of guards shall be not less than,
(a) 920 mm for required exit stairs, and
(b) 1 070 mm around landings.
(6) The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1 500 mm.
(7) The height of guards for stairs and landings shall be measured vertically from the top of the guard to,
(a) a straight line drawn tangent to the tread nosings of the stair, or
(b) the surface of the landing.
v2 O. Reg. 88/19
Later · 2022-01-01(1) Except as provided in Sentences (2), (3), (4) and (6), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units, other than guards serving spiral stairs, shall be not less than 900 mm high.
(3) Exterior guards serving a house or an individual dwelling unit shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(4) Guards for flights, except in required exit stairs, shall be not less than 900 mm high.
(5) Reserved
(6) The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1 500 mm.
(7) The height of guards for flights shall be measured vertically from the top of the guard to a straight line tangent to tread nosings served by the guard.
1 January 2025: the code in force today
O. Reg. 163/24 is one page. It adopts the National Building Code of Canada 2020, as amended by a separate document that the ministry re-issues under a new date whenever it changes. Guard height keeps the number 9.8.8.3. Ontario replaces one sentence and adds another.
OBC2024 is not in our corpus yet due to copyright, so this is the one text on the page we quote instead of render.
9.8.8.3. Height of Guards (See Note A-9.8.3.3.)
(1) Except as provided in Sentences (2) to (3.1), all guards shall be not less than 1 070 mm high.
(2) All guards within dwelling units or within houses with a secondary suite including their common spaces shall be not less than 900 mm high.
(3) Exterior guards serving not more than one dwelling unit or a house with a secondary suite including their common spaces shall be not less than 900 mm high where the walking surface served by the guard is not more than 1 800 mm above the finished ground level.
(3.1) The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1 500 mm.
(4) The height of guards for flights of steps shall be measured vertically from the top of the guard to a line drawn through the tread nosing served by the guard.
Sentence (2) answers our question: 900 mm on flights, landings, and since they no longer have an exception, spiral stairs.
Check this yourself
Every comparison above names both versions, both in-force windows and the regulation behind each one, and opens on our comparison page. How to read the band explains each mark. Our sources lists what we hold and where each edition was obtained.
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The 2024 text comes from the 2024 Building Code Compendium, and the 2024 figures from O. Reg. 163/24 and the Ontario Amendments to the National Building Code of Canada 2020, both published by the Ministry of Municipal Affairs and Housing. CodeChronicle is not an official version of the Ontario government.
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