AS 1288 Requirements for Glass in Buildings

What AS 1288 covers

AS 1288:2021 (Glass in buildings - Selection and installation) is the standard that architects, builders, glaziers, and building surveyors use to determine glass requirements for any building project in Australia. The NCC references AS 1288 as the deemed-to-satisfy solution for glazing compliance.

The standard covers glass selection for wind loads, human impact safety, overhead glazing, glass barriers and balustrades, framing requirements, and thermal stress assessment.

Human impact safety requirements

The human impact provisions of AS 1288 are the most commonly applied sections. They require safety glass in locations where a person could fall into or against a glazed panel.

Safety glass is classified as either Grade A (higher impact resistance) or Grade B (lower impact resistance). The grade required depends on the location:

• Grade A safety glass is required in doors, sidelights beside doors, panels in walls and partitions below 500mm above floor level, and bathrooms
• Grade B safety glass may be acceptable in some applications where the risk is lower

Safety glass types include toughened (tempered) glass and laminated glass. Both meet Grade A requirements when correctly manufactured and tested.

Overhead glazing

Overhead glazing has specific requirements because a failure drops glass fragments onto people below. The 2024 amendments to AS 1288 strengthened these requirements:

• Grade A laminated safety glass is now mandatory for all sloped overhead glazing, with limited exceptions
• Three-sided support requirements have been expanded
• Toughened glass alone is generally not acceptable for overhead applications because it shatters into small fragments that fall as a mass

Laminated glass is preferred because the interlayer holds broken fragments together, preventing them from falling. Where toughened glass is used overhead, it must be combined with a retention system or be part of an insulated glass unit where the inner pane provides retention.

Glass barriers and balustrades

Glass used as a barrier (where falling from height is a risk) must comply with both the structural load requirements for barriers under the NCC and the impact safety requirements under AS 1288.

The 2024 amendments expanded the requirements for:

• Spigot-fixed barriers (glass panels held at the base by metal fittings)
• Point-fixed barriers (glass held by bolt-through fixings)
• Core-drilled barriers
• Barriers with and without handrails

Glass barriers at heights of 1,000mm or more must use toughened laminated glass or an equivalent specification that provides both impact resistance and post-breakage retention.

Wind load glass selection

AS 1288 provides the methodology for selecting glass thickness based on wind loads. The process requires:

• Determination of the design wind pressure for the specific building location and height (from AS/NZS 1170.2)
• Selection of glass type and thickness that will resist the design pressure with the required safety factor
• Consideration of the support conditions (two-sided, three-sided, or four-sided support)

Larger panels, higher buildings, and more exposed locations require thicker glass or stronger glass types.

Thermal stress assessment

Thermal stress occurs when part of a glass panel is heated by direct sunlight while the edges remain cool (shaded by the frame). AS 1288 requires thermal stress assessment for glass in locations where partial shading is expected.

If the thermal stress exceeds the edge strength of the glass, toughened or heat-strengthened glass must be specified instead of annealed glass. Toughened glass has roughly four times the thermal stress resistance of annealed glass.

What this means for building owners

If your building was constructed before the current edition of AS 1288, some glazing may not meet current requirements. This does not necessarily mean immediate replacement is required, but it should be assessed during facade inspections. If glass is being replaced for any reason, the replacement glass must comply with the current edition of AS 1288.

References

• AS 1288:2021: Glass in buildings - Selection and installation (including 2024 amendments)
• NCC Volume One: Glazing requirements for commercial buildings
• AS/NZS 2208:1996: Safety glazing materials in buildings
• AS/NZS 1170.2: Wind actions