Engineering check for an NCC 2025 Performance Solution (A2G2) against F1P1 (Class 2 to 9) or H2P1 (Class 1 and 10): grade line check (Colebrook–White), with the AS/NZS 3500.3:2025 Section 11 rules (New Zealand)
AS/NZS 3500.3, which NCC 2025 calls up for roof drainage (Volume One F1D3, Volume Two H2D6(1)(a) and, for plumbing work in Tasmania and Victoria, Volume Three E3D2), sets charged-line rules for New Zealand only, so in Australia this check supports a Performance Solution under A2G2 against F1P1 (Class 2 to 9) or H2P1 (Class 1 and 10); in Tasmania, Volume Three TAS B7D3(2) calls up the Director's Guidelines for charged downpipes to rainwater tanks supplying drinking water on Class 1 and 10 buildings.
An engineering check, not the Standard's deemed-to-satisfy method. Use it to understand a design or to support a Performance Solution under NCC 2025 A2G2.