Breezway takes compliance with the Construction Code and relevant Standards seriously. Our Altair Louvre Windows are designed and tested to exceed the requirements of NZS 4211-2008 “Windows in Buildings”.

NZS 4211-2008 Product Performance Warranty

Altair Louvres are designed to exceed the requirements of NZS 4211-2008 ”Windows in Buildings”.

The following table outlines the maximum variations that Breezway will warrant per Rating Category. Exceeding these constraints will void this Warranty. The limitations have been generated through NATA test results. The design constraints below apply to Altair Louvre Components used in New Zealand manufacturer’s framing systems.

For commercial applications, please consult Breezway with your specific project requirements, so we can correctly apply the relevant performance warranty constraints.

A window manufacturer will be able to label its Altair Louvre Window products to comply with NZS 4211 when assembling Altair Louvres to Breezway procedures and operating within the following performance warranty constraints.

Breezway Design manual AS2047

Window Energy Ratings

Breezway Altair Louvre Windows can help to enhance the energy efficiency and comfort of a building by offering:

Maximum Ventilation
With no fixed panes and blades that open almost fully horizontally (87º) Altair Louvre Windows welcome fresh, cooling breezes. These cooling breezes reduce the need for power hungry electric air conditioning systems, thereby helping to save our fragile environment.

Tight Sealing
Altair Louvre Windows have an air infiltration rating that is significantly better than the standard required for residential windows. Tight sealing reduces draughts thereby allowing heating and cooling systems to run more efficiently.

Compliance With Clause H1
Compliance with Clause H1 of the New Zealand Building Code is possible in most Climate Zones when Altair IGLU Double Glazed Louvre Windows are used. Altair IGLU Double Glazed Louvres in NZ JMF Pine Framing have been simulated in accordance with ISO 10077 with an average R-Value of 0.48. Large assemblies can offer higher R-Values.
Breezway is currently working with New Zealand Aluminium System Suppliers to develop Altair IGLU Double Glazed Louvre in Thermally Improved Aluminium Framing.

Compliance With Earlier Versions of Clause H1
For building approvals prior to 3rd November 2022, Altair Single Glaze Louvre windows may be used.

For more information, we have a range of Technical Bulletins and Performance Reports available on the energy ratings of different blade types from our Downloads page.

Breezway tinted green louvre blades

Warm Climates

The shading offered by tinted glass or timber blades reduces the amount of hot sunlight entering a building and has a positive impact on the window’s energy rating.

Breezway louvres in bathroom

Cold & Mixed Climates

The insulating properties of clear low e glass blades give comparative thermal performance to clear double glazing.

Breezway louvres fixed window

Extreme Climates

Louvre/Fixed combinations are great for achieving good ventilation and very low U-values.

breezway louvres screens


External metal mesh screens can deliver additional insulating and shading benefits to Altair Louvre Windows.

The tabs provide a range of technical information relating to window energy ratings. For further details view the Breezway Design Manual
Altair Louvres meet U-value requirements for energy efficiency in all climate zones.

WERS Certified Products Directory – AFRC (available at

Blade TypeWERS Windows IDWERS Glazing CodeWERS Cooling Stars6WERS Heating Stars6Uw3SHGC4Tvw5

Breezway Altair Louvre Components in a timber frame - Single Glazed1

Breezway Altair Louvre Components in a timber frame - Single Glazed1

6mm thick clear glassBRZ-005-016Clr4.90.580.62
6mm thick grey tinted glassBRZ-005-026Gy4.90.410.29
6mm thick super grey tinted glassBRZ-005-066SoGy4.90.250.06
6mm thick bronze tinted glassBRZ-005-036Bz4.90.440.34
6mm thick evergreen tinted glassBRZ-005-046EG4.90.370.47
6mm thick arctic blue tinted glassBRZ-005-056AB4.90.370.37
6mm thick clear low E glass2BRZ-005-136LE3.40.490.57
6mm thick Sunergy glass2BRZ-005-146Sn3.70.420.48

Breezway Altair IGLU Louvre Components in a Timber Frame – Double Glazed

5mm Planibel G (#2)10 / 12mm Argon / 5mm Planibel G (#3)10BZW-012-015PbG/12Ar/5PbG2.60.40.43

Ratings by co-principal developer of WERS Dr Peter Lyons
Based on WERS calculation methodology but beyond current AFRC procedures (not available at, only available at


  1. Results disclosed at Australian Fenestration Rating Council (AFRC) regulations.
  2. These blades have a microscopically thin low emissivity coating that is invisible to the naked eye and improves insulation and reduces solar heat gain.
  3. Results disclosed in Standard International Units. Results calculated to the procedures of WERS Screen Rating Methodology, 2012.
  4. These ratings are not authorised WERS ratings and should be regarded as a research report, they have been generated using the WERS calculation methodology but are beyond current AFRC procedures. Calculated performance indices are suitable for comparison with information on the WERS database.
  5. As the optical properties of cedar timber and aluminium are not contained in the International Glazing Databse (IGDB), known, default properties were used.
  6. Uw is the whole window U-value.
  7. SHGCw is the whole windows solar heat gain co-efficient.
  8. Tvw is the whole window visible (light) transmittance.
  9. Star ratings calculated using Nationwide House Energy Rating Software (AccuRate) according to procedures of WERS 2008.
  10. Numeric values next to Low E glasses e.g. (#2) and (#3) refer to the coated surface of the glazing layer. Secondary glazing figures are treated as two individual glass layers with two surfaces each. Double glazed figures are treated as a single unit with four surfaces. Surfaces counted externally to internally.
  11. The glazing is reported in the same orientation as it is simulated so that the outside is always on the left, inside is always on the right.

Static Performance (Uw SHGCw Tvw Tdw) calculated using Window 6.3 and Therm 6.3 software (LBNL), 1999-2010.

Window Fall Prevention and Barriers

Restricted openings
Altair Louvre Windows can be restricted to comply with F4/AS1 2.1.1 or 2.1.2 of the New Zealand Building Code, where a 100mm diameter sphere must not be able to pass through the openable window.

Imposed Loads
Altair Louvre Windows have undergone testing to the design loads set out in Clause 3.6 and Table 3.3 AS/NZS 1170.1 “Structural Design Actions” for imposed loads on barrier infills. In situations where concentrated loads greater than 187N must be withstood Altair Louvres must be specified to include the Stronghold System which mechanically fixes blades into the Altair Stronghold Clips.

To see all the Altair Louvre Window configurations that comply please refer to the Breezway Design Manual.

Please note: Altair Louvres with restricted openings or when using the Stronghold System are permanent fixtures which cannot be removed, unlocked or overridden without complex tool usage. Products that can be unlocked or overridden with a simple tool, or by a two-handed operation will require additional barriers to 865mm.

Altair Louvre Windows are not a balustrade system. Nor are any other window types. Balustrades are one type of barrier. Altair Louvres with the Stronghold System or with restricted openings are another. It is important to ensure that a particular barrier system complies with the relevant Building Codes and associated Standards.