Per the international building code, a minimum handrail height from top of rail to nosing is ______.

The following figure depicts typical stairway and barrier members and associated terminology. Some items have been omitted for clarity.

Figure 3.9.2.0 Typical stairway and barrier members

Legend:

1. Stringer
2. Baluster
3. Barrier
4. Tread
5. Riser
6. Landing
7. Handrail
8. Newal post
9. Open riser
10. Winders (tapered treads)
11. Handrail
12. Landing barrier
13. Barrier

For a required barrier to an external trafficable structure in an alpine area, the requirements of this Part need to be read in conjunction with the requirements of Part 3.10.4. Safety barrier requirements for swimming pools are contained in Part 3.10.1.

In addition to the requirements of this Part, a barrier and handrail must comply with the structural requirements of Part 3.0. The structural requirements refer to the barrier and/or handrail being designed and constructed to withstand any combinations of loads and other actions to which it may reasonably be subjected and the structural resistance of the materials and forms of construction used for the barrier or handrail.

A window forming a part of a barrier must comply with the glazing assembly provisions of Part 3.6, and therefore is not required to comply with AS/NZS 1170.1 (structural design actions - referenced in Part 3.0) as it is exempted by Part 3.6. The Part 3.6 provisions consider the wind loading on the glazing and human impact requirements.

Figure 3.9.2.1 Barriers-when required

Figure 3.9.2.2 Barriers-when required for retaining walls

1. 3.9.2.4 addresses requirements regarding location, height and extent of handrails. Where a barrier and handrail are installed together, 3.9.2.4 is to be read in conjunction with 3.9.2.2, 3.9.2.3 and 3.9.2.5.
2. A handrail is required on at least one side of the stairway flight or ramp. The top rail of a barrier may be suitable as a handrail if it meets 3.9.2.4 and is able to be grasped by hand to provide support to the person using the stairway or ramp.
3. 3.9.2.4(a)(ii) requires a continuous handrail which must extend the full length of the stairway flight or ramp except where the handrail is associated with the barrier, in which case the handrail can terminate where the barrier is allowed to terminate. This allows for the barriers to geometric stairways such as elliptical, spiral, circular or curved stairways to finish a few treads from the bottom of the stairway.
4. 3.9.2.4(a)(iii) requires a minimum handrail height of 865 mm. This height provides comfort, stability, support and assistance for most users.
5. 3.9.2.4(b) outlines where a handrail need not be provided, this includes—

• where a stairway or ramp is providing a change in elevation less than 1 m; or
• a landing for a stairway or ramp; or
• winder in a stairway if a newel post is installed to provide a handhold.

A wire barrier is deemed to meet the requirements of 3.9.2.3(c) if it is constructed in accordance with the following:

Figure 3.9.2.5 Protection of openable windows—bedrooms

The intent of 3.9.2.6 and 3.9.2.7 is to reduce the risk of a person (especially a young child) falling through an openable window.

Where the floor level below an openable window in a bedroom is less than 2 m there are no specific requirements. For an openable window 2 m or more above the surface beneath, openable windows are required to restrict passage of a 125 mm sphere using any one of the following design solutions:

1. The window be designed such that any opening does not allow a 125 mm sphere to pass through (e.g. louvres) and be capable of resisting a 250 N force when directed against the window.
2. The window be fitted with a fixed or dynamic device that is capable of restricting the window opening so it does not allow a 125 mm sphere to pass through and is difficult for a young child to operate. The restricting device must be capable of resisting a 250 N force when directed against the window such as a casement window or in attempting to push a sliding window open. An internal screen with similar parameters may be installed.
3. The window be fitted with an internal or external screen that does not allow a 125 mm sphere to pass through and which must resist a horizontal outward force of 250 N.

If the openable part of the window is at least 1.7 m above the floor, no further protection is required.

Where a device or screen is securely fixed in position (e.g. a screen pop riveted to the window frame) so it cannot be unlocked, overridden, or is very difficult to remove without for example a drill, the 865 mm barrier would not be required as the securing method is considered a fixture and not a child resistant release mechanism. 3.9.2.6(b)(ii)(C relates to a screen or window restricting device protecting an openable window in a bedroom. The screen or opening restricting device may be installed in a manner that allows it to be removed, unlocked or overridden in the event of a fire or other emergency to allow safe egress. In these situations the unlocking device must be child resistant.

Child resistance could be achieved by the need to use a tool, key or two hands.

There are a number of hardware options available. Short chain winders and barrier screens will allow windows to comply with this requirement. Sliding window locks may lock a sash so a 125 mm sphere cannot pass through. Where provision is made to fully open the window beyond 125 mm then the child resistant release mechanism is required in addition to the device resisting a 250 N force as required by 3.9.2.3(b)(ii)(B).

3.9.2.6 in addition prescribes that an 865 mm barrier (sill) would be required. A wall beneath an openable window or fixed glazing under the openable part of a window which meets the height requirements (e.g. transom at least 865 mm above the floor) can be considered as the barrier if the criteria in 3.9.2.6 are met.

A wall beneath an openable window or fixed glazing under the openable part of a window which meets the height requirements (e.g. transom at least 865 mm above the floor) can be considered as the barrier if the criteria in 3.9.2.7(b) are met.

The term "window" is not italicised in 3.9.2.6 and 3.9.2.7 and as such, is not restricted to the definition of "window" in the NCC. The reason for this is to also capture windows that may let in air but not light, e.g. metal louvres. A metal louvre or openable panel would not fit in the NCC definition of window but is subject to the window barrier provisions.