Amid increasing world awareness that impacts of climate change present a clear and present danger to our future generations, the debate about what measures Australia can take to mitigate the risks, persistently ignores adoption of a relatively straightforward avenue that would have a significant impact on the sustainability of our built environment..
Since 2010, when the Building Products Innovation Council (BPIC) released its Life Cycle Inventory paper, Life Cycle Assessment has been recognised as an effective basis for improving the environmental impact of building products choices with regard to “embodied energy” – the upstream value of the energy consumed by the process of building production, from mining and processing of natural resources through to manufacturing and transport. Embodied energy is the front-end component of the lifecycle impact of a building – and it is the part that can never be changed.
Why is this important? Five to seven percent of global CO2 emissions are caused by cement production. The iron and steel sector account for 11 percent of global CO2 emissions. And more than five percent of the world’s entire electrical generation is spent on the production of aluminium.
In Australia, the Green Star points system has successfully created awareness and incentives for building owners to market the operational performance of commercial buildings. However, the points awarded for construction materials choice is hugely lacking. The Design as Built section of its assessment scorecard is not only insufficient as a potential motivator of sustainable choices, it nowhere near reflects real potential CO2 impacts. Structural steel attracts the same point score as timber products for instance and each is awarded only a maximum of one percent of a potential total score.
Notwithstanding the impacts of post-construction operation on life-cycle carbon of fossil fuel-based buildings, embodied impacts could contribute up to 22 percent of a building’s total impact. The key determinant of this is the nature of materials used for building construction. Embodied impacts of buildings can be very significant and could contribute up to 60 percent of their life cycle impacts, as they become more energy-efficient during their operational stage.
I have confirmed these impacts myself in modelling undertaken for my company Tecbuild Systems, by Planet Ark in 2012. Based on a real-project case study, demonstrated a 75 percent reduction of embodied energy for a timber framed floor system as against a concrete slab for a first floor addition.
There is clearly a disjunct between current Green Building accreditation and the potential impacts of construction materials choices on a sustainable outcome. It is my view that the current tokenistic acknowledgement of materials impacts must be changed. New policy measures based on a whole life assessment methodology, instead of the current dominant importance placed on just operational impacts of buildings should be adopted as priority.
As renowned timber architect Michael Green asserts, green carpet, green roofs, solar panels—they’re relatively minor fixes.” Building with wood, he says, would not only limit the creation of carbon dioxide associated with the production of concrete and steel, but it also has another benefit – carbon storage. With timber construction, carbon remains stored for the life of the building. A typical timber-frame house stores 28 tons of carbon dioxide, roughly the amount emitted by a mid-size car over seven years.
With buildings becoming more energy-efficient during their operational stage, there is an urgent need for an increased focus on the embodied impacts of buildings. If the election in Australia is indeed the Climate Election as some assert, I call on parties to recognise the importance of this issue and put an forward appropriate embodied energy policy.
 World Bank -International Finance Corporation-Edge Buildings.com 30/8/17
 Athena Foundation (Canada) modelling