Weather Resistant Louvres A medium weight louvre for high rise plantroom applications. A popular louvre on many New Zealand buildings. * Free Area % Chart Louvre Widths: 0.300 to 0.900 - 1.000 to 2.500 * Free Area m2 Chart Louvre Widths :0.300 to 0.900 - 1.000 to 2.500