Higher star ratings will add little extra cost.
The energy efficiency of our homes is on the rise again. Last year, state and federal governments agreed to lift the residential standard from five to six stars. The changes will come into the national building code from this May, and then the states must bring them into effect by May 2011, at the latest.
In Victoria, the new rules are the first major increase since the introduction of the five-star regulations in 2004. So what difference does a star make?
It’s only a small rise in cost for a cushy lift in comfort, according to the CEO of VicUrban, Pru Sanderson. With its builder partners, the state land development agency has been offering six-star homes for years. “They’ve become VicUrban’s base standard,” she says. “We’ve proven to the market that it is doable, at scale, for a very, very small price tag.”
VicUrban estimates that the better performing homes will cost $5000 extra at the most, but much less – under $2000 – if the planning, subdivision and orientation of the blocks is done carefully. “In terms of the cost of a home, it’s a very small outlay for a long-term benefit,” Ms Sanderson says. “We estimate that a six-star house uses about 15 per cent less energy in heating and cooling compared with a five-star house.”
Matt Fisher, from the Association of Building Sustainability Assessors, says the price tag could be even lower. “We did some studies that looked at real world [plans] and found that they could be increased from five to six stars for about $500,” he says.
The last jump in energy efficiency rules forced the industry to improve the building fabric and insulation. Mr Fisher says that this time around, the changes will summon designs that better suit the climate and location of the house.
David Hallett, from Archicentre, the building advisory service of the Australian Institute of Architects, agrees. He argues that the house plans and the site of the land must always be considered together. “Most of our homes are designed in isolation and plonked on a block, depending on which floor plan the client happens to like. Sometimes it works well, and sometimes, really badly.”
Poorly oriented homes may still be able to reach six stars, but they’ll need top-notch windows and insulation. It will be much cheaper for new homes to meet the higher standard if they are well-suited to their block – with features such as smaller windows to the west and south, living areas to the north, and eaves calculated to shade over summer and let in sun over winter.
The ideal way to address local conditions is with a custom design that fits your land. But Ms Sanderson maintains that big builders and developers can also offer well-oriented houses at scale – though the industry will first have to invest in expanding the range of its products. “At VicUrban we already have sophisticated guidelines about typical building configurations for different kinds of blocks,” she says.
Although Ms Sanderson approves of the higher standard, she’s also quick to point out that the new regulations don’t mean we’ll consume less energy. “The improved performance is being offset by the ever-increasing size of new houses,” she says. “The average new house is 40 per cent larger now compared with the 1970s.” Bigger homes not only chew through more energy, but also more construction materials and waste.
Likewise, the way we live in the house has a drastic effect on the amount of energy we consume. “We’re wasting our time doing all of this if we don’t help educate people about how to live in a more environmentally attuned way,” Ms Sanderson says. “We want the six-star lifestyle to go with the six-star house.”
Renovating with the stars
The six-star regulations will also apply to extensions. Retrofitting energy efficiency is more difficult than starting from scratch, but Anthony Wright, building designer at Sunpower Design, says the higher standard is well within reach. “We generally aim for seven stars or better – six stars is a minimum.”
The new rules are slated to work the same way as the current five-star renovation system, which applies only to projects that require a building permit and varies depending on the size of the alteration. For larger additions the whole house must comply, while for smaller changes only the new part must adhere to the rules. “You’re not required to do the impossible,” Mr Wright says.
To make the grade, he says designers will need to incorporate solar passive design techniques, including smart orientation to get sun in winter and exclude it in summer. That task can be tricky for additions to the shady south. “Sometimes it requires more thought, but there are lots of ways to get northerly sun in a southern extension, such as using roof glazing or setting the extension back.”
Mr Wright has two main tips for would-be renovators. “Do a preliminary energy rating at the sketch design stage to see whether the designer is coming close. It might cost a few hundred dollars, but could save you a lot of grief down the track,” he says. “And be realistic about the amount of glazing you put into the house and the direction it faces. Think strategically about it, rather than having expanses of glass.”