b'STEP 1DETERMINING CORRECT WIND SPEEDStep 1.4Topographic EffectThis step measures the effect of wind on a proposed structure based on its site location on a slope, ridge, mountain or escarpment, then the actual height/slope of that particular location. Topographic classifications are divided into zones T0, T1, T2, T3, T4 and T5. Use the following table to determine the applicable topographic classification of a proposed structure. If the slope, ridge, mountain or escarpment exceeds 30 metres please refer to AS 4055:2021.TOPOGRAPHICCLASSIFICATION SITE LOCATION ON SLOPE / MOUNTAIN / RIDGE / ESCARPMENTEFFECTMAXIMUM SLOPE OFLOWERMIDTOP THIRDOVER TOPMOUNTAIN / RIDGE / ESCARPMENT THIRD THIRDLess than 1:20(2.9 o ) T0 T0 T0 T0 T0 T0Greater than & equal to 1:20 to Less than 1:10( 2.9 oto < 5.7 o ) T0 T0 T1 T1 T1 T0Greater than & equal to 1:10 to Less than 1:7.5 T0 T1 T1 T2 T2 T0( 5.7 oto < 7.6 o )Greater than & equal to 1:7.5 to Less than 1:5( 7.6 oto < 11.3 o ) T0 T1 T2 T2 T3 T1Greater than & equal to 1:5 to Less than 1:3( 11.3 oto < 18.4 o ) T0 T2 T2 T3 T4 T2Greater than & equal to 1:3 (18.4 o ) T0 T2 T3 T4 T5 T312Delta Panels Pty.Ltd. ABN: 11 147 861 292A: 731 Boundary Road, Richlands, Qld 4077 Version Date: P: +61 7 3271 2170 E: info@deltapanels.comW: www.deltapanels.com 08.05.2023'