scope:

Inclusions

This technical specification specifies requirements for the classification and associated testing of windows installed in the external walls of New Zealand buildings.

The classification of as-manufactured windows relative to exposure categories is intended to facilitate the selection and specification of windows used in:

(a) Buildings for which the building wind zone is determined in accordance with NZS 3604 or NASH standard - Part 2: Light steel framed buildings and for which the weathertightness of the window installation in the cladding system is demonstrated using an acceptable solution or verification method for New Zealand Building Code (NZBC) clause E2 External moisture;

(b) Other buildings within the scope of NZS 3604 or NASH standard - Part 2: Light steel framed buildings, and for which the building wind zone is determined in accordance with those documents, for which the weathertightness of the window installation in the cladding system is demonstrated using an alternative solution for NZBC clause E2 External moisture;

(c) Buildings for which cladding wind pressures on the windows have been determined using AS/NZS 1170.2. For these buildings, the weathertightness of the window installation in the cladding system can be demonstrated using an acceptable solution, verification method, or alternative solution for NZBC clause E2 External moisture.

This technical specification covers performance in terms of exposure categories related to test pressures for wind and water penetration resistance, and in terms of air permeability. Additional tests are also required for operating force, torsional rigidity of opening panels, and behaviour following lateral displacement for some configurations and circumstances.

The lateral displacement test provides an assessment of the resilience of the test specimen. It is not intended to be a full assessment of seismic performance and makes no assessment of performance in ultimate limit state (ULS) seismic events.

AS/NZS 4284 provides additional methods for undertaking seismic assessment of a facade.

While BRANZ's study report 54 (Thurston, 1994) showed that windows in timber-framed houses are likely to 'ride out' ULS seismic displacements without collapse or losing their structural integrity, more recent work (Carradine, et al., 2020) has identified that this risk cannot be ignored, since window systems in New Zealand have been shown to be susceptible to significant damage as evidenced in recent earthquakes. Hence, lateral displacement testing has been added to the suite of tests.

Exclusions

This technical specification specifically excludes:

(a) Skylights, rooflights, and roof windows;

(b) Interior windows and doors;

(c) Fixed louvres;

(d) Building facades (including curtain walls);

(e) Large access doors such as roller-shutter doors and grilles;

(f) Automatic entrance doors;

(g) Thermal and acoustic performance;

(h) The weathertightness of the window perimeter junction with the external wall or facade;

(i) Durability;

(j) Security performance.

The performance of skylights, rooflights, and roof windows can be tested using AS 4285.

The performance of garage doors and large access doors can be tested using AS/NZS 4505.

Performance outcomes addressed by this technical specification are intended to be applied to fire windows installed in the external walls of buildings. However, this technical specification does not address their fire performance.