Glazing refers to the installation of glass (or transparent/translucent materials) into frames such as windows, doors, partitions, skylights, and façades. In practice, it includes the glass unit, frame, sealants, spacers, and the installation method (Construction Dictionary, Your Home).
Why Glazing Matters
- Thermal performance & energy efficiency: Poor glazing increases heat loss/gain and raises energy costs (Your Home).
- Natural light & comfort: Good glazing balances daylight with glare and heat control.
- Safety & code compliance: Safety glass (toughened, laminated) is required in impact areas per the NCC (NCC Part 3.6).
- Acoustic control: Multi-pane glazing reduces noise in high-traffic or urban areas.
- Aesthetics: Coatings, tints, and patterns allow glazing to match function and design.
Types of Glazing
| Type | Description | Strengths / Use Cases |
|---|---|---|
| Single Glazing | One pane of glass | Lowest cost, minimal insulation, suited to non-critical areas |
| Double Glazing (IGU) | Two panes separated by a spacer, sealed with air or inert gas | Better thermal & acoustic performance, now standard in many new builds |
| Triple Glazing | Three or more panes with spacers | High efficiency for extreme climates, heavier and more expensive |
| Specialty Glazing | Toughened, laminated, low-E, tinted, patterned | Added safety, solar control, style or noise reduction |
Key Performance Metrics
- U-value (Uw/ Ug): Lower = better insulation (AWA Glass Guide).
- Solar Heat Gain Coefficient (SHGC): Fraction of solar energy transmitted; lower is better for hot climates (Your Home).
- Visible Light Transmittance (VLT): Percentage of visible light passing through glazing.
- Rw rating: Sound insulation performance (higher = better acoustic control).
- Air infiltration: Amount of air leakage through the unit; tight seals improve performance.
Regulations & Standards in Australia
- NCC Part 3.6 & 8.4: Rules for glazing size, safety, and human impact (NCC).
- AS 1288:2021 Glass in buildings – Selection & installation: Standard for thickness, support, loads, and safety (Preview).
- WERS (Window Energy Rating Scheme): Provides energy ratings for window systems in Australia.
The Glazing Process
- Design & specification: Select glass type, orientation, wind load, safety zones.
- Frame preparation: Ensure frames are square, plumb, and structurally sound.
- Glass fabrication: Cut to size, assemble IGUs with spacers and seals.
- Installation: Set into frame with blocks, gaskets, sealant.
- Finishing: Seal edges, mark safety glass, test for water/air penetration.
Practical Tips
- Check WERS ratings when comparing products.
- Use low-E coatings on east/west windows for solar control.
- For noise, choose laminated or acoustic IGUs.
- In coastal areas, ensure marine-grade frames and fixings.
- Factor in lifespan: IGU seals usually last 15–25 years before failing.
- Confirm existing frames can accommodate thicker double or triple glazing before retrofitting.
Sources: Your Home – Glazing, National Construction Code, HIA, AWA Glass Guide