━━ red line = waterproofing membrane. Waterproof all wet areas to AS 3740 & NCC 2022 Part H4 / F. Floors: the entire bathroom/laundry floor is waterproofed (timber floors must have the whole floor membraned). Three floor wastes — one centred in the shower, one in the main bathroom floor and one in the laundry — each floor plane graded to its waste at a continuous fall between 1:80 (minimum fall) and 1:50 (maximum fall) per AS 3500.2 / NCC 2022. Step-free hobless shower (Livable Housing) — set-down / recessed substrate so the finished shower floor is flush, with a point/linear drain. Membrane up-turns: shower walls ≥1800 high; all other wet-area walls ≥150; behind/around vanity & over any hob/step ≥150; turn into the floor waste & around all penetrations. Substrate: wet-area floor = compressed fibre-cement sheet (or set-down) on the timber floor; walls = villaboard / wet-area plasterboard. Tile over; flexible sealant to all internal junctions & penetrations. Livable Housing (NCC H8): hobless step-free shower; grab-rail reinforcement (12 mm ply or 25 mm timber noggings) in the shower & toilet walls; basin ≥450 from the pan centreline; 1200×900 clear in front of the pan. Ventilation (Part 10.6 / 10.8): the bathroom & laundry are internal (no external window) so each has its own mechanical exhaust fan ducted to OUTDOOR AIR (not the roof space), ≥25 L/s, with Zone-7 run-on (Part 10.8). Natural-vent alternative (openable area ≥5% of floor) is not available here. Preliminary — confirm membrane system, falls, substrate & fan flow/run-on with the waterproofer/certifier.