Safety glass is one of those building materials most homeowners don't think about until something goes wrong — but getting it right can literally save lives. In New Zealand, the Building Code sets out clear rules about where safety glass must be used, and understanding these requirements can help you stay compliant whether you're renovating, replacing a broken pane, or building new.
What Is Safety Glass?
Safety glass is glass that has been manufactured or treated so that, if it breaks, it does so in a way that significantly reduces the risk of serious injury. There are two main types used in NZ residential and commercial buildings:
Toughened (Tempered) Glass
Toughened glass is heat-treated to make it several times stronger than standard float glass. When it does break, it shatters into small, relatively blunt pebbles rather than sharp shards. This makes it far less likely to cause deep lacerations. You'll often see a small etched mark in the corner confirming it meets the relevant standard.
Laminated Glass
Laminated glass consists of two or more panes bonded together with a plastic interlayer (usually PVB). When broken, the fragments tend to stick to the interlayer rather than flying free. Laminated glass is commonly used in overhead glazing, skylights, and situations where the glass must remain in place after breakage (for example, to maintain a weather barrier or prevent a fall).
What About Wired or Patterned Glass?
Older wired glass (glass with embedded wire mesh) was once considered a safety product, but it is no longer accepted as safety glass under current NZ standards. If you have wired glass in a critical location, it likely needs replacing.
The NZ Building Code and Relevant Standards
In New Zealand, glazing requirements are primarily governed by Clause F4 (Safety from Falling) and Clause F2 (Hazardous Building Materials) of the NZ Building Code. The key technical standard is NZS 4223: Glazing in Buildings, which sets out exactly which glass types and thicknesses are acceptable in which situations.
BRANZ provides research and guidance that supports how these standards are applied in practice. It's worth knowing that compliance with NZS 4223 is one of the accepted ways to demonstrate compliance with the Building Code for glazing.
Where Is Safety Glass Legally Required?
Under NZS 4223 and the Building Code, safety glass is required in critical locations — areas where a person is likely to come into contact with the glass or where breakage could cause a fall. These include:
- Doors and sidelights — any glazing in or immediately beside a door, particularly within a certain distance of the door opening and below a specified height from the floor
- Low-level glazing — glass panels that extend close to floor level (generally below 1500 mm from the floor in high-traffic areas) where someone could walk or fall into them
- Shower screens and bathroom enclosures — wet areas where slipping is a real risk; safety glass is mandatory here
- Balustrades and pool fencing — glass used as a barrier must be toughened or laminated (and meet specific thickness and fixing requirements)
- Stairwells and landings — glazing adjacent to stairs where a fall through the glass could cause serious injury
- Overhead glazing and skylights — laminated glass is typically required so fragments don't fall on people below
- Schools, early childhood centres, and other public buildings — often have additional or more stringent requirements
The specific dimensions and thresholds (how close to a door, how low to the floor, etc.) are defined in NZS 4223, so always check the standard or consult a glazier for your exact situation.
How to Identify Safety Glass
Most compliant safety glass will have a permanent etched or sandblasted mark in a corner, showing the manufacturer, the standard it meets (e.g. AS/NZS 4667 for toughened glass), and the glass type. If you're unsure whether existing glazing in your home is safety glass, a qualified glazier can assess it for you.
Renovating or Replacing Glass — What You Need to Know
If you're replacing glazing as part of a renovation, the replacement glass must meet current Building Code requirements — even if the original glass didn't. This is a common surprise for homeowners: you can't simply replace like-for-like if the original installation was non-compliant or if standards have changed.
A building consent may be required depending on the scope of work. Minor like-for-like replacements in the same opening often fall under exempt work, but adding new glazed openings or changing the size of existing ones generally requires consent. Check with your local council or visit MBIE Building Performance for guidance on what requires consent.
Healthy Homes and Rental Properties
If you're a landlord, be aware that unsafe glazing in a rental property could also be considered a hazard under the Healthy Homes Standards. While the Healthy Homes Standards focus primarily on heating, insulation, ventilation, moisture, and draught stopping, general building warrant of fitness and safety obligations still apply.
When to Call a Professional
Glazing work in critical locations — doors, balustrades, pool fencing, shower screens, and overhead glazing — should always be carried out by a qualified glazier. While homeowners can sometimes replace a straightforward window pane in a non-critical location, correctly identifying whether a location is critical, selecting the right glass type and thickness, and installing it to code requires expertise.
Getting it wrong isn't just a compliance issue — it's a genuine safety risk. A licensed glazier will know NZS 4223 inside out, can certify their work, and will ensure your home is safe and legally compliant. You can find qualified local glaziers on tradedirectory.co.nz.