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Engineering · Building codes

Guard and handrail code by location.

Building code requirements for guard and handrail systems in British Columbia and Alberta. Sales-ready summaries; engineer of record verifies on every project.

00

Common questions

Plain-English answers to the questions sales hears most. The technical clauses below carry the citations; the engineer of record signs off on every project.

  • Does Cable Series 3 meet code?

    Yes. Cable Series 3 is engineered to the same NBC 2020 guard load envelope as the picket and glass lines — 0.75 kN/m distributed or 1.0 kN concentrated horizontally, 1.5 kN/m vertically, and 0.5 kN over 100mm × 100mm on individual elements. Cable spacing under load must not permit passage of a 100mm sphere; the engineer of record sets tension, intermediate-support spacing, and maximum permitted deflection per project.

    See clausesNBC 2020 §4.1.5.14(1)NBC 2020 §4.1.5.14(2)NBC 2020 §9.8.8

  • How high does my guard have to be?

    It depends on the occupancy and the drop. Within or serving a single dwelling unit, the minimum is 900mm where the drop is not more than 1800mm. In all other Part 9 locations and in Part 3 buildings — commercial, institutional, multi-unit residential common areas, exterior balconies and roofs accessible to the public — the minimum is 1070mm.

    See clausesNBC 2020 §3.4.6.5NBC 2020 §9.8.8.3

  • Do I need 42in railings on a second-story deck?

    On a single-family residential deck where the drop from the deck surface to the surface below is more than 1800mm (about 5ft 11in), yes — the minimum guard height is 1070mm (42in). If the drop is 1800mm or less, the 900mm (36in) minimum applies for a guard within or serving a single dwelling unit. A standard second-story deck on a 9ft first floor is well past the 1800mm threshold, so 42in is the working assumption.

    See clausesNBC 2020 §9.8.8.3

  • What is the difference between Part 3 and Part 9?

    Part 3 of NBC 2020 covers large or complex buildings — commercial, institutional, and most multi-unit residential. Part 9 covers Housing and Small Buildings — houses, duplexes, small low-rise residential, and small buildings under 600 m² and three storeys. Norcut spec pages flag whether a clause is Part 3 or Part 9 so the engineer of record applies the right rule for the occupancy on the permit.

    See clausesNBC 2020 §3.4.6.5NBC 2020 §9.8.8

  • Are 100mm picket gaps acceptable?

    Up to 100mm is the limit. Openings through any required guard — including the space between the bottom rail and the surface protected — are sized so that they will not permit the passage of a 100mm spherical object. Picket Series 1 ships at a default spacing tighter than this limit; cable spacing is set per project under load by the engineer of record.

    See clausesNBC 2020 §9.8.8

  • Do I need a handrail on every stair?

    For Part 9 stairs, at least one handrail is required on stairs with more than two risers within a single dwelling unit, and on both sides of stairs more than 1100mm wide serving other than a single dwelling unit. Ramps require at least one handrail. Part 3 stair requirements are generally more stringent — engineer of record confirms per occupancy.

    See clausesNBC 2020 §9.8.7.1NBC 2020 §9.8.7.4

  • What load does a guard need to resist?

    For general locations other than grandstands and assembly viewing stands, the minimum horizontal load at the required height is 0.75 kN/m distributed or 1.0 kN concentrated at any point, whichever governs. The vertical load is 1.5 kN/m at the top, and it does not act simultaneously with the horizontal load. Individual elements — pickets, panels — are designed for 0.5 kN over a 100mm × 100mm area at any point.

    See clausesNBC 2020 §4.1.5.14(1)NBC 2020 §4.1.5.14(2)NBC 2020 §4.1.5.14(3)

  • Does an engineer of record have to sign off on the guard?

    Yes. The code values on this page are sales-side summaries. The engineer of record on each project confirms the applicable occupancy, the active sub-clause under the current provincial edition (BC Building Code 2024 or NBC(AE) 2023), and that the as-built guard meets the cited loads, heights, infill, and graspability requirements at the time of permit issuance.

    See clausesNBC 2020 §3.4.6.5NBC 2020 §9.8.8NBC 2020 §9.8.7

Applicable code · Alberta

National Building Code – 2023 Alberta Edition · NBC(AE) 2023

Effective May 1, 2024 · NBC 2020 with Alberta variations

National Research Council of Canada — under contract with the Government of Alberta · Enforced by Safety Codes Council of Alberta.

View source →
01

Minimum guard height — Part 3 buildings

  • NBC 2020 Division B §3.4.6.5

    Guard height — Part 3 buildings

    In a Part 3 building, the minimum guard height is 1070mm, measured vertically from the surface protected. Reduced heights are permitted in specific locations such as means of egress on the assembly side of seats in assembly occupancies.

    Applies toCommercial, institutional, and large residential (Part 3) buildings — common areas, balconies, exterior decks and roofs accessible to the public.

02

Minimum guard height — Part 9 buildings

  • NBC 2020 Division B §9.8.8.3

    Guard height — within a single dwelling unit

    A guard installed within or serving a single dwelling unit may be a minimum of 900mm where the surface protected is not more than 1800mm above the adjacent surface. Where the drop exceeds 1800mm, the 1070mm minimum applies.

    Applies toInterior stairs, balconies, and decks within or serving a single dwelling unit (Part 9 housing).

  • NBC 2020 Division B §9.8.8.3

    Guard height — other Part 9 locations

    For all Part 9 locations other than within or serving a single dwelling unit — including multi-unit residential common areas — the minimum guard height is 1070mm measured vertically from the surface protected.

    Applies toMulti-unit Part 9 buildings, common balconies, exterior stairs serving more than one dwelling unit.

03

Specified loads on guards

  • NBC 2020 Division B §4.1.5.14(1)

    Horizontal load on guards

    For locations other than open viewing stands, grandstands, stadia, bleachers, arenas and means of egress in those locations, the minimum specified horizontal load applied inward or outward at the minimum required height of every required guard is 0.75 kN/m, or a concentrated load of 1.0 kN applied at any point, whichever governs.

    Applies toAll Part 3 and Part 9 guards in general locations.

  • NBC 2020 Division B §4.1.5.14(2)

    Vertical load on guards

    The minimum specified load applied vertically at the top of every required guard is 1.5 kN/m, and it does not need to be considered to act simultaneously with the horizontal load.

    Applies toAll required guards.

  • NBC 2020 Division B §4.1.5.14(3)

    Load on individual elements of guards

    Individual elements of guards — including solid panels and pickets — are designed for a concentrated load of 0.5 kN applied over an area of 100mm × 100mm at any point so as to produce the most critical effect.

    Applies toPicket, panel, and individual infill elements within a guard.

  • NBC 2020 Division B Table 9.8.8.2

    Specified loads on Part 9 guards

    Within and serving a single dwelling unit, guards resist a horizontal load of 0.5 kN/m or a 1.0 kN concentrated load, whichever governs. In all other Part 9 locations, the horizontal load is 0.75 kN/m or a 1.0 kN concentrated load. The vertical load is 1.5 kN/m in both cases.

    Applies toPart 9 guards (housing and small buildings).

04

Infill openings and climbability

  • NBC 2020 Division B §9.8.8

    100mm sphere infill rule

    Openings through any required guard — including the space between the bottom rail and the surface protected — are sized so that they will not permit the passage of a spherical object having a diameter of 100mm. Sub-clause lettering for this rule varies between editions; engineer of record to confirm under current provincial code.

    Applies toPicket spacing, cable spacing under load, glass frame gaps, bottom-rail clearance.

  • NBC 2020 Division B §9.8.8

    No-climb requirement

    Guards required by the Code are designed so that no member, attachment or opening located between 100mm and 900mm above the surface protected facilitates climbing. Sub-clause lettering varies between editions; engineer of record to confirm.

    Applies toAll Part 9 guards. The Part 3 equivalent is in NBC §3.4.6.5; engineer of record to confirm applicability per occupancy.

05

Handrail height

  • NBC 2020 Division B §9.8.7.1

    Where handrails are required

    At least one handrail is required on stairs with more than two risers within a single dwelling unit, and on both sides of stairs more than 1100mm wide and serving other than a single dwelling unit. Ramps require at least one handrail.

    Applies toPart 9 stairs and ramps. Part 3 requirements are stated in NBC §3.4.6.4 and are generally more stringent.

  • NBC 2020 Division B §9.8.7.4

    Handrail height — stairs and ramps

    The height of a handrail on a stair is measured vertically from a line drawn through the outside edges of the stair nosings, and is between 865mm and 965mm. The height of a handrail on a ramp or landing is measured vertically from the surface and is between 865mm and 965mm.

    Applies toHandrails on stairs, ramps, and landings in Part 9 buildings. Part 3 cross-references the same height range.

06

Handrail graspability

  • NBC 2020 Division B §9.8.7.5

    Handrail graspability

    A handrail is continuously graspable along its entire length. A circular cross-section is between 30mm and 43mm in outside diameter; non-circular sections have a graspable cross-section with a perimeter between 100mm and 125mm and a largest cross-sectional dimension not exceeding 45mm.

    Applies toAll required handrails on stairs and ramps. Continuous graspability is verified by the engineer of record at each terminus and intermediate landing.

07

Recent revisions

  • May 1, 2024

    National Building Code – 2023 Alberta Edition came into force. Replaces the NBC(AE) 2019 edition. Adopts NBC 2020 as the technical base and aligns with the National Energy Code for Buildings 2020 (NECB 2020). All permit applications from this date forward are reviewed under NBC(AE) 2023.