In a Class 1 building the risks from water vapour and condensation must be managed so that their effect on occupants' health is minimised. Verification Method H4V5 shows that a mould index above 3 (as defined in Section 6 of AIRAH DA07) does not occur on the inner face of the water control layer or on building fabric inside it, using AIRAH DA07 input assumptions and its intermediate method for indoor design humidity. Deemed-to-Satisfy route: H4D9, condensation management to Housing Provisions Part 10.8 (vapour permeance of pliable membranes by climate zone, roof space ventilation, and exhaust discharge to outdoors). From 1 May to 30 September 2023 NCC 2019 provisions could be used instead; Tasmania points designers to its Condensation in Buildings Tasmanian Designers' Guide.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.