Bathroom plumbing rules in Victoria
In Victoria, hot water at bathroom taps must be limited to 50°C for new and replaced hot water installations, usually with a tempering valve. Every tap, shower and toilet must be WaterMark certified, and the plumbing must be done by a licensed plumber. A bathroom renovation that keeps the same layout often needs no building permit, but moving walls or structure can.
Hot water: 50°C at the bathroom
The Victorian plumbing regulator requires water used for personal hygiene, mainly bathroom taps, showers and baths, to be delivered at no more than 50°C. It is done with a tempering valve to AS 4032.1, or a water heater built not to exceed 50°C. The limit is 45°C in childcare centres, schools and aged care.
It applies to all new heated water installations: a first-time install, replacing a heater, moving one, or extending the hot water to new fixtures. The exception is a like-for-like heater replacement in the same place where the old installation didn't need a valve, such as an unaltered house built before 5 August 1998. Kitchens and laundries can be left hotter.
WaterMark and WELS
Taps, showers, toilets and other products connected to the water supply must be WaterMark certified, or a plumber can refuse to install them. Taps, showers and toilets also need a WELS water rating label. See WaterMark and WELS explained.
Water pressure
The plumbing standard limits the pressure at outlets inside a house to 500 kPa. Where mains pressure is higher, a pressure-limiting valve is fitted at the meter. Most mixers work best between about 150 and 500 kPa; ask us if your house has low-pressure gravity hot water.
Who does the work
Plumbing, including moving a waste or water point, must be done by a licensed plumber, who certifies the work when it is finished. Hard-wired items such as heated towel rails need a licensed electrician. Waterproofing follows its own standard: see bathroom waterproofing requirements.
Permits
Replacing fixtures in the same positions usually doesn't need a building permit. Moving or removing walls, changing structure or adding a bathroom can. A registered building surveyor can tell you before you start.