AS 2047 Water Tightness Ratings: Seven Window Types Evaluated

Key Australian Standards & QLD References

• AS 2047 – Windows and External Glazed Doors: Performance testing requirements including water penetration, air infiltration, and structural strength.
• AS/NZS 4284 – Testing of Building Facades: Full façade/system testing of water, air, and structural performance.
• National Construction Code (NCC) – Damp & Weatherproofing (Part H2): Regulatory framework for moisture resistance and weatherproofing.
• QBCC Guidelines: Guidance on window selection, installation, and certification in Queensland.
• QRA / Cyclone Resilience Guidance: Requirements for cyclone-prone and exposed coastal areas.
• Wintec Systems Technical Reference: Industry guidance on window performance and testing.

Water Penetration Resistance Values (AS 2047)

Comparison of Seven Window Types

Window Type Analysis

Casement Window

Compression seals around the sash increase water resistance as wind pressure pushes the sash tighter. Excellent for QLD coastal and high-rise applications.

Awning Window

Top-hinged outward-opening design forms a downward slope that naturally blocks rain, allowing ventilation even in rainy conditions.

Tilt-Turn Window

Multi-point locking with full perimeter seal ensures top-tier water tightness. Ideal for exposed or cyclone-prone zones.

Sliding Window

Water can accumulate in bottom tracks, and brush seals are less effective under wind-driven rain. Suitable only for low-exposure façades.

Double-Hung Window

Two movable sashes create multiple leakage paths; high precision in sealing is required. Not recommended for exposed coastal façades.

Bi-Fold Window

Multiple panels and hinges create sealing challenges. Only premium systems with reinforced stiles, concealed hardware, and weather-rated thresholds achieve reliable water resistance.

Parallel Push Window

Evenly distributed pressure on perimeter seals improves water resistance. Performance is comparable to awning windows.

Practical Advice for Queensland Projects

• Site wind‐pressure and exposure assessment: During design, have a qualified engineer assess the building’s ULS, SLS and exposure classification (non-exposed, exposed, shielding, cyclone-prone) according to AS 4055 or AS/NZS 1170.2. The QBCC fact sheet explicitly mandates that these details be specified when ordering windows. 

• Obtain and verify AS 2047 test reports: When procuring windows, insist that suppliers provide third-party NATA-accredited AS 2047 test certification, including water-penetration results. 

• Detail waterproofing in installation: Ensure proper design and installation of flashing, drainage channels, and pressure rails. These details are critical for real-world water resistance.

• On-site QA testing: Post-installation, consider on-site water spray testing (or equivalent) to validate the actual water-tightness.

• Maintenance plan: Regularly inspect gaskets, weep holes, flashing, and hardware, especially for coastal or high-salt environments where seals and metal components may degrade.

Conclusion

Queensland’s climate demands high water tightness for windows. Tilt-turn, casement, awning, and parallel push windows provide excellent performance, while sliding and double-hung are best for low-exposure or sheltered façades. Bi-fold systems must be premium engineered for coastal applications.