The NZ Metal Roof and Wall Cladding Code of Practice is a comprehensive design & installation guide, and a recognised related document for Acceptable Solution E2/AS1 of the NZ Building Code.
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.
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.
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.