The IPCC ARC6 report clarifies that the world is heating, current policies are not enough to keep the world at 1.5o hotter than the pre-industrial world and that Australia will be around 4o hotter.
It is well documented that the energy efficiency of households can be improved by:
- simple design features; and
- the adoption of energy efficient appliances and lights.
The National Construction Code (NCC) sets the minimum standard for houses built in Australia. It includes the National House Energy Rating Scheme ( NatHERS) with a minimum of 6 stars. Building houses to a higher energy standard means that these houses will be:
- more comfortable and healthy to live in;
- save $200 to $900 annually in reduced energy use; and
- significantly reduce greenhouse gas emissions that contribute to the global warming.
By 2050, our climate is going to become much hotter and half the houses then standing will be built after 2019. It is therefore essential build homes to a higher NatHERS level than the minimum 6 stars.
In the period 2019 to 2020 nearly 30% of new houses built in Gympie Regional Council area were below the current NCC standard. The average NatHERS in 2020/21 was 6.6, exactly where it was in 2016/17 according to CSIRO data. In contrast, Rockhampton started at 6.9 and moved up to 7.5 with no buildings below the NCC standard built in 2019 to 2020. Gympie needs to emulate Rockhampton.
The NCC is being reviewed now for adoption in 2022. The changes being proposed will require a National House Energy Rating Score (NatHERS) of 7 or more, up from the current 6. This will be based on a whole of house assessment, based on the thermal build as well as the nature of the appliances within the house, the efficiency of the major energy appliances in the house, i.e. air conditioners and water heaters and the solar PV system installed. The aim is to have the house energy use below 68 MJ/sqm/annum (18.9 kWh/sqm/annum). These houses do cost slightly extra to build and this cost is recovered over time due to the reduced energy use and cost.
The NCC review is also including methodology to assess the NatHERS of existing homes to help guide house purchasing and renovations to gain the maximum benefits.
The update NCC has now been approved with a staged application of the new requirements.
On the NatHERS and the your home websites are great resources to help you get the best house designed to a high standard. Various calculators and checklists and design plans and specifications exist to help you get to a high NatHERS score for your new home as well as existing structures.
You can enter your own data and get an assessment on your house at NABERS.
Everyone building, planning, designing or renovating houses should be adopting a NatHERS score of 7 or higher. These homes will be more comfortable and have lower running costs.