COP:natural-light; clause-g7-nzbc

10.1 Clause G7 NZBC 

NZBC Clause G7 Natural Light requires habitable spaces to have enough natural light though windows and roof lights to safeguard against illness with anough visual awareness of the outside to prevent feelings of isolation.

1. 'The workplace must have suitable and sufficient lighting'.
2. 'The lighting must, so far as reasonably practical, be by natural light.'

All plastic sheets used with profiled metal cladding in New Zealand should comply with AS/NZS 4256.1 and should be tested in accordance with 17.3 Material Density, Melting Point, Expansion And Modulus.

The most common form of roof lighting used in commercial and industrial buildings comprises of single skin matching profiled translucent sheets, running from ridge to eave. Alternatively, discontinuous profiled sheets placed in a chequerboard pattern, barrel-vaults or domes can be fitted on both sloping and flat roofs. All plastic roof lighting materials are supplied with films or surface coatings,  stabilisers for durability, and long-term resistance to weathering and the discolouration termed 'yellowing'.
Roof lights are available to match metal profiles in a range of thicknesses and fire resistant grades. They are differentiated according to structural and safety requirements and imposed loadings.
Roof Lights should comply with the test provisions of AS/NZS 4257.
Only full-length roof lights running from ridge to eave must be used with unpainted galvanized roof cladding to avoid inert catchment corrosion.

To maintain water-tightness and avoid thermal distortion, roof lights should be installed within the spanning capability of the profile, which depends on the profile shape and thickness. Additional support can be obtained from adjacent metal cladding by the use of mid-span supports (see 13.8.4 Midspan Supports)or alternately the thickness of the roof lights should be increased.

Safety mesh should be provided under all translucent sheeting which is accessible and more than 500 mm wide.