Ethically sourced timbers are another sustainable option to use in residential construction. ‘It’s a renewable resource and, if sourced and milled responsibly, is probably the most sustainable building material available,’ says architect Ben Callery, director of Ben Callery Architects.
Various bodies exist to certify where and how timber has been sourced, including the Forestry Stewardship Council (FSC). ‘This is a worldwide not-for-profit group that investigates and audits supply chains for timber, and uses sustainability as one of its 10 key parameters,’ says Angus Crisp. ‘We also as a company prefer to use Australian timbers rather than imported, as to also reduce any carbon miles from shipping.’
Likewise with brick, using recycled timbers from the outset is the best way for consumers to minimise their environmental impact when building.
A downfall of timber is its lack of thermal mass, but Ben Callery assures this material can still be an effective insulator. ‘Thermal mass isn’t an essential in sustainable design. Some of the most thermally efficient buildings in cold climates in Europe don’t use thermal mass at all – the focus is more on higher levels of insulation,’ he says.
The sustainable qualities of concrete are complicated. On the one hand, concrete is a versatile material that offers good thermal mass, but on the other, it’s very energy intensive to produce. ‘Unfortunately, the main material used in concrete, cement, has a very high carbon cost. The steel reinforcement required in concrete also has high carbon costs,’ says Angus Crisp.
To reduce the environmental impact of concrete, look for varieties with some recycled content. ‘We’re very mindful of the embodied energy of concrete, and try to use concrete with recycled content where possible,’ says Ben Callery. ‘But, if the building is going to be there for a long time and the thermal mass will contribute to the performance energy efficiency of the building, then that can start to offset that embodied energy,’
In partnership with Bank Australia, we’re bringing you ‘Building Better’ – a series aimed at demystifying sustainable renovation ideas and building upgrades. Revisit our previous stories on solar power and interior design.
If you like building better and are interested in green homes, Bank Australia’s Clean Energy Home Loan offers a discounted home loan rate if you buy or build a home that exceeds a 7-star NatHERS rating, or have made ambitious green upgrades in the last 12 months. Find out more.