Glass balustrades are a popular choice for modern designs due to their sleek appearance and ability to provide safety without obstructing views. In New Zealand, the use of glass balustrades is governed by specific regulations under the New Zealand Building Code (NZBC) and other relevant standards.
1. Height Requirements for Glass Balustrades
- General Requirements (NZBC Clause F4: Safety from Falling):
- Balustrades must be at least 1 meter high for residential buildings.
- For commercial or public buildings, the height must be at least 1 meter for stairs and 1.1 meters for other areas.
- Pool Fencing (Fencing of Swimming Pools Act 1987):
- Pool fences, including glass balustrades, must be at least 1.2 meters high to prevent unsupervised access by children under 5.
- The gap between the bottom of the balustrade and the ground must not exceed 100mm.
2. Glass Balustrades Around Pools
- Safety Requirements:
- Glass balustrades used as pool fences must comply with NZBC Clause F9: Means of Restricting Access to Residential Pools.
- The glass must be safety glass (either toughened or laminated) to prevent injury if broken.
- The balustrade must not have horizontal elements that could be climbed by children.
- Glazing Standards:
- Glass must meet AS/NZS 2208: Safety Glazing Materials in Buildings.
- For pool fences, the glass must be Grade A safety glass (either toughened or laminated).
- Spacing and Gaps:
- Gaps between glass panels or between the glass and the ground must not allow a 100mm sphere to pass through.
3. Glass Balustrades in Bathrooms
- Privacy and Safety:
- In bathrooms, glass balustrades may be used for showers or as partitions.
- Frosted or textured glass is often used to provide privacy while allowing light to pass through.
- Glazing Standards:
- Glass used in wet areas (e.g., showers) must be safety glass to prevent injury if broken.
- Compliance with AS/NZS 2208 is required.
- Height Requirements:
- If the balustrade is part of a shower enclosure, it must be at least 1.8 meters high to prevent water splashing outside the shower area.
4. Glazing Standards for Glass Balustrades
- Safety Glass Requirements:
- Glass balustrades must use safety glass that complies with AS/NZS 2208.
- Toughened Glass:
- Breaks into small, blunt pieces to reduce injury risk.
- Must be at least 6mm thick for balustrades.
- Laminated Glass:
- Consists of two or more layers of glass bonded with a PVB interlayer.
- If broken, the glass fragments adhere to the interlayer, reducing injury risk.
- Must be at least 6.38mm thick (e.g., 2 x 3mm glass layers with a 0.38mm interlayer).
- Thickness and Strength:
- The thickness of the glass depends on the height and span of the balustrade.
- For balustrades up to 1 meter high, 8mm toughened glass or 6.38mm laminated glass is typically used.
- For balustrades over 1 meter high, thicker glass (e.g., 10mm toughened or 8.38mm laminated) may be required.
- Edge Finishing:
- Glass edges must be smooth and polished to prevent injury.
- Edges can be seamed, pencil-polished, or arrised for safety.
5. Design and Installation Considerations
- Frameless vs. Framed:
- Frameless Glass Balustrades:
- Provide a clean, modern look but require robust fixing systems (e.g., spigots or channels).
- Framed Glass Balustrades:
- Use metal or timber frames to hold the glass panels, providing additional support.
- Frameless Glass Balustrades:
- Fixings and Supports:
- Glass balustrades must be securely fixed to the floor or structure to withstand lateral loads (e.g., wind or human impact).
- Fixings must comply with NZBC Clause B1: Structure.
- Handrails:
- Handrails are not always required for glass balustrades but may be needed for stairs or ramps to comply with NZBC Clause D1: Access Routes.
6. Compliance and Inspections
- Building Consent:
- Glass balustrades generally require a building consent, especially if they are part of a pool fence or structural element.
- Inspections:
- The balustrade must be inspected during and after installation to ensure compliance with the NZBC and relevant standards.
- Certification:
- Installers should provide certification that the glass meets AS/NZS 2208 and other relevant standards.
Summary of Key Requirements
| Context | Height | Glazing Type | Standards | Additional Requirements |
|---|---|---|---|---|
| General | 1.0m (residential) | Toughened or laminated | AS/NZS 2208, NZBC F4 | No climbable elements, smooth edges |
| Pool Fencing | 1.2m | Grade A safety glass | AS/NZS 2208, NZBC F9 | Max 100mm gaps, no horizontal elements |
| Bathrooms | 1.8m (showers) | Frosted/textured glass | AS/NZS 2208 | Privacy, water resistance |
| Glazing Standards | N/A | Min 6mm toughened/6.38mm laminated | AS/NZS 2208, NZBC B1 | Secure fixings, polished edges |
Conclusion
Glass balustrades are a versatile and stylish option for various applications, but they must comply with strict safety and performance standards in New Zealand. Key considerations include:
- Height requirements for different contexts (e.g., pools, bathrooms).
- Use of safety glass (toughened or laminated) that meets AS/NZS 2208.
- Compliance with NZBC clauses (e.g., F4, F9, D1, B1).
- Proper installation and inspection to ensure safety and durability.
Always consult with professionals (e.g., architects, builders, or glazing specialists) to ensure your glass balustrades meet all legal and safety requirements.