Since the last upgrade to residential energy efficiency requirements of the National Construction Code (NCC) in 2010, power bills have soared and technologies and design options for energy efficient homes have improved.

Yet the next increase in stringency requirements for new housing is unlikely to take place until 2022. The NCC 2019 Public Comment Draft released by the Australian Building Codes Board (ABCB) includes greater requirements for energy performance in commercial buildings and some improvements to residential in areas such as split heating and cooling loads, sealing and condensation management. But it does not increase the stringency of requirements for household energy performance. Accordingly, until the next updating cycle in 2022, new homes will continue to be built to requirements set almost a decade ago.

According to a new report, this is concerning. Released by ClimateWorks Australia in conjunction with the Australian Sustainable Built Environment Council (ASBEC), the interim report of the Building Code Energy Performance Trajectory Project says straightforward improvements in areas such as air-tightness, ceiling fans and roof insulation could deliver 28 to 51 per cent reductions in energy costs associated with heating and cooling homes and household cost savings worth up to $150 per annum. This would equate to improvements of between 1 and 2.5 stars on the NatHERS scheme.

With more than half a million new homes expected to be built over the next three years, the report cautions that delaying these improvements would lock in an extra $1.1 billion in unnecessary energy bills and three million tonnes of additional carbon emissions between now and 2050.

Eli Court, implementation manager, ClimateWorks Australia said Australia said the lack of stringency increases for almost a decade comes despite advances which had enabled cost effective improvements to be achieved.

He says tougher requirements would deliver not only lower household costs but also cost-effective environmental benefits. Lower household energy demand, meanwhile, will help alleviate power supply pressures and avoid or delay the need to build expensive new energy infrastructure. It will also help minimise the need to spend money on new renewable assets to meet climate change targets. Finally, greater thermal comfort and performance in new homes will have important health benefits for vulnerable residents who will be less exposed to weather extremities.

Court says efficient homes are an important way in which energy cost savings can be delivered.

“There has been a lot of attention on energy prices going up, but we haven’t improved the energy efficiency requirements of the homes in almost 10 years, and we are unlikely to (have done so) for 12 years in terms of the National Construction Code,” he said.

“There have been real advances in technology and building design approaches in that period. We have had areas of clear demonstration where people have had very high levels of efficiency at very low costs. It doesn’t make sense that we are delaying for so long.”

Tony Arnel, chair of the ASBEC National Construction Code Working Group says Australia is having a ‘light-bulb’ moment in which the need to ‘use less’ is being recognised despite the political focus around sources of energy supply.

Arnel says improvements in aforementioned areas had been demonstrated through ClimateWorks research to be cost effective.

“We are finally asking the question ‘what if we use less?’ We have had focus on the supply side of the debate and it has been very political and confusing for many people,” he said.

“The question now is ‘what if we used less and save hundreds of dollars per household and at the same time avoid expensive infrastructure investment and reduce greenhouse gasses along the way?’

“Finally, the penny is dropping about using less energy.”

In their report, ClimateWorks and ASBEC argue that benefits can be achieved through tighter requirements for air leakage. At the moment, the Code does require residential buildings to include features which minimise leakage and does set out requirements for common air leakage points such as exhaust fans, windows and doors to be sealed. Nevertheless, it does not specify minimum performance levels which need to be achieved. Introducing these and associated verification methods would be an important first step, it says.

Other initiatives would involve increasing roof insulation for detached housing and using ceiling fans to reduce the need for air conditioning in warm and hot climates.

During research conducted by ClimateWorks, each of these measures were found to reduce household energy bills (using conservative estimates) by between $45 and $150 per year. This is even without considering opportunities for accelerated adoption of best-practice building design such as optimal building orientation and window placement – strategies not considered in the report as these are far from current mainstream practice.

The report calls for tougher residential energy requirements to be included in the NCC by 2022 at the latest, as well as market transformation initiatives to reduce the cost of further energy saving initiatives, the introduction of renewable energy requirements into the Code, and measures to improve Code compliance.

In a statement provided to Sourceable, Australian Building Codes Board general manager Neil Savery said the approach adopted for NCC 2019 reflects policy direction given to the Board by governments in 2016. This, Savery said, has resulted in proposals for greater stringency for commercial buildings in NCC 2019 which Savery says could reduce energy consumption and greenhouse gas emissions by 40 per cent over current requirements.

As for residential, he said the National Energy Productivity Plan foreshadowed the need for further research given as available research at time demonstrated that the need for a stringency increase in 2019 was not as strong as was the case for commercial buildings (it is widely anticipated that a residential stringency increase will occur in 2022). At any rate, Savery says initiatives included for NCC 2019 are ‘not insignificant’ and go a long way toward addressing issues identified in the report notwithstanding the absence of a stringency increase.

“It is a position of fact, reported at the time, that in 2016, policy direction of governments was provided to the ABCB to increase the stringency of the commercial building energy efficiency provisions for NCC 2019,” he wrote.

“The National Energy Productivity Plan foreshadowed the need for further research on residential buildings given that the research available at the time demonstrated that the case for a stringency increase was much less for residential buildings than for commercial buildings.

“On this basis, the ABCB developed a work plan for residential buildings that involved strengthening the provisions in NCC 2019 without applying a stringency increase. For example, the planned introduction of NatHERS heating and cooling load limits, together with improvements to the reference building Verification Method and the building sealing provisions, are not insignificant. These planned changes, which form part of yesterday’s release of the NCC 2019 public comment draft, go a long way to address some of the issues in the interim report.

“At the same time, the public comment draft features a substantial body of work that has been undertaken since 2016 in developing the enhanced energy efficiency measures for commercial buildings, which if adopted, have the potential to reduce both energy consumption and greenhouse gas emissions by up to 40% in new buildings over current requirements.

“The release of NCC 2019 public comment draft today incorporates the amendments that are proposed for NCC 2019, which have been developed prior to the cut off date for new content. Any new work undertaken by the ABCB in relation to residential energy efficiency beyond these measures requires policy direction and involve a rigorously tested rationale, the analysis of verifiable evidence, development of what can be regarded as a proportional response and subjected to consultation and regulatory impact analysis. This will not occur for NCC 2019.”

Property industry lobby groups agree that action on energy efficiency is needed.

Property Council of Australia chief executive officer Ken Morrison says the initiatives identified in the report could have a significant impact with only very modest costs.

Furthermore, Morrison says starting now on a gradual trajectory of stringency requirement rises will head off a ‘stop-start’ approach which is disruptive for the construction sector and which sees sudden ‘jumps’ in stringency requirements followed by years of inaction.