Following many discussions with our members, Master Builders has sent a letter to Lily D’Ambrosio, the Minister for Energy, Environment and Climate Change.

The letter asks for the removal of the requirement for the fitting of gas boosted solar hot water or rainwater tanks in addition to the 6 Star requirements.

Currently, Volume 2 of National Construction Code 2019 (NCC) includes a state variation for Victoria for Part 3.12.0(a). 

This variation prescribes that all new dwellings (Class 1 buildings) are to include a rainwater tank connected to all sanitary flushing systems, or a solar water heater system, installed in accordance with the Plumbing Regulations 2018. 

Choosing an alternative hot water service is only permissible if certain other conditions are met, which in effect limit the flexibility of other more suitable energy efficient options.

Essentially if a solar water heater system is preferred to a rainwater tank, and reticulated gas is readily available to the property; then the solar water heater system can only be gas boosted.

Encouraging the installation of solar gas boosted hot water services made some sense in 2005 when it was first introduced into the NCC to reduce emissions from Victoria’s predominantly brown coal sourced electricity. 

In 2021 the case for retaining this limiting requirement is much weaker for several reasons.

Firstly, developments in heat pump electric hot water systems have increased their efficiency.

Secondly the increase of renewable energy sources means the carbon intensity of Victoria’s electricity is decreasing rapidly.

Further, a low emissions electric hot water system (LEEHWS) will, when paired with solar PV, in many cases, be the less carbon intensive option.