Australia National Construction Code 2022 Volume Two (Building Code of Australia, Class 1 and 10 Buildings) WA-H6-H10: Western Australia: Amendment 1 energy efficiency for existing buildings and eaves gutter changes (WA Part H6, WA Part H10)

NCC 2022 Amendment 1 (effect 1 May 2025) inserts WA Part H6: for alterations and extensions to an existing Class 1 building or attached Class 10 part that did not have to meet the NCC 2022 energy efficiency requirements, and for a pool associated with such a building, NCC 2019 Volume Two Amendment 1 Part 2.6 and Part 3.12.5 may be applied instead of Part H6. It also inserts WA Part H10, which varies AS/NZS 3500.3:2021 in Western Australia: clause 3.5.1 is replaced so that eaves gutters and downpipes must be designed and installed so water does not flow back into the building, with overflow measures allowed in accordance with Housing Provisions Part 7.4, and Table 3.5.2 is replaced with a downpipe sizing table that permits a 95 mm by 45 mm rectangular downpipe. Related WA Housing Provisions variations cover eaves gutter falls and brackets, a 10 mm gap above windows in framed walls, climate zone 6 treated as zone 5 for Parts 13.2 and 13.3, and insulation of attached Class 10a buildings and projecting upper floors in climate zones 4 and 5.