Higher-performing uPVC windows that balance optimisation of heating and cooling loads with consumers’ desire for greater natural light should be actively encouraged as the energy-efficient and cost-effective solution for Australian homes.
That’s the view of the Vinyl Council of Australia responding, on behalf of its uPVC Window Alliance members, to consultation on proposed changes to the National Construction Code (NCC) 2019.
Strongly supporting the aim to improve energy efficiency of the built environment, the Alliance believes that windows, as a key building element, offer significant, cost-effective opportunities to strengthen commercial and residential energy requirements in Australia.
Vinyl Council Chief Executive Sophi MacMillan points out that Australia’s current standards are ‘low in comparison to the UK and Europe’ and there is currently ‘little incentive’ for builders or landlords to create energy-efficient properties.
“Yet homes have a fundamental impact on occupant health and wellbeing – and the capacity of the energy market,” she says. “The built environment presents opportunities to make significant in-roads to achieving Australia’s commitment to reduce emissions to net zero by 2050 under the Paris Agreement on climate change.”
But lack of regulatory certainty on future updates to energy requirements would discourage industry from innovation and investing in improved products that would deliver better energy efficiency in the move towards net zero emissions, Sophi warns.
In supporting the introduction of regulations that incorporate heating and cooling load limits, the Alliance highlights the role windows play in a building’s thermal performance and, just as crucially, its aesthetics.
According to research by the CRC for Low Carbon Living, 87% of consumers want a home filled with natural light and 85% want a cool home in summer and a warm home in winter. Studies have also shown that consumers are willing to pay more to achieve this.
“We have some concerns that a ‘least cost option’ approach may overly emphasise smaller windows as a solution to meet the heating/cooling load limits,” comments Sophi. “Natural light is valued by residents. It is unrealistic to expect consumers to accept housing design with smaller windows when research proves otherwise.
According to the Alliance, there are higher-performing window systems (Uw Values of <4 W/m2K) available in Australia that outperform basic double-glazing for a similar cost. Use of the lowest performing, single-glazed metal-framed windows may cut costs but, in our view, should be discouraged.
Sophi continues: “The solution is to optimise heating and cooling loads – and natural light – by encouraging the use of higher-performing, double-glazed windows that with larger glazing areas can deliver year-round thermal benefits, as well as improved security and acoustic insulation.”
The Alliance has contributed to a report by ASBEC and ClimateWorks Australia: ‘The Bottom Line – household impacts of delaying improved energy requirements in the Building Code’. The report highlights the urgency of updating the stringency of energy efficiency requirements that if done now through cost-effective measures, could cut heating and cooling energy use by up to 51 percent.