The ABCB have been very helpful in highlighting the changes in the NCC 2019 and 2022 versions, recently they have released an advisory note on NCC 2022 Gutter-downpipe-provisions-for-housing
For Class 1 buildings, the NCC Volume Two & Housing provisions provides the reference for Performance Requirements, with either a D-t-S or PS compliance. However, in 2022 the NCC have provided and alternate D-t-S reference being ABCB Housing Provisions Standard. Thus, in relation to Storm Water management designers and builders can reference AS3500.3 or the Housing Provisions Standard (Part 3.3 Drainage – 3.3.3 Surface water drainage; 3.3.4 Subsoil drainage; 3.3.5 Stormwater drainage; PLUS, Part 7.4 Gutters and Downpipes)
Main changes:
- Updated tables on rainfall intensity
- Changes to support brackets to gutters
- Valley gutters require a minimum 15mm freeboard limit
- Box Gutters on roofs less than 12.5 degrees
- Only D-t-S on Box Gutters is AS3500.3 or a Performance Solution
Note that the design on Subsoil & Stormwater drainage will provide an impact on below ground construction, particularly ‘liveable space’ construction for Waterproofing Design. This situation generally requires a Performance Solution (PS) Waterproofing Strategy document, which we are happy to assist.
