The life cycle of a new building starts long before any bricks have been laid, and so too does its carbon footprint. Consider the machinery, the materials and transport to and from the building site as well as all those bright lights beaming up into the sky.
With all those emissions to be accounted for, ensuring that all contractors are on the same page from the start of the project will reduce the building’s carbon footprint and save you from a “green headache” later on.
The Green Building Council of Australia’s executive director, Robin Mellon, says we need to look at carbon through the whole process of a project.
“We can look at it at lots of different stages of a building’s life cycle,” he says. “We can look at educating people better on the site and the waste management issues onsite, so that when you’re building you’re actually being much more sensible with the materials and things are being properly recycled.”
Mellon says while the building is being occupied, about three-quarters of its emissions will come from daily operations, but during construction half the carbon emissions are from machinery.
“So there’s a lot of opportunity here that we need to be targeting directly and then targeting indirectly through better education,” he says.
Besides the machinery, a lot of emissions stem from the materials used and getting the building materials to the site.
“What we find really encouraging is that already we have project teams who are looking very closely at what they’re doing and how,” he says. “And it’s this sort of analysis and self-awareness and education which is probably helping these project teams to look at, for example, how they all get to site.”
Producing a green travel plan, car pooling, and looking at the delivery route of materials can reduce carbon emissions.
“So the economies of scale and thus the economies of environment are becoming clear and that’s before you’ve even thought about what the materials that you’re using are: the concrete, the steel, the timber, and studying the embodied energy or the emissions or the carbon footprint of those,” Mellon says.
He also suggests considering the land use and ecology of the site and issues such as light pollution from the development, which can affect local biodiversity and insect life.
As energy efficiency of buildings improves overall, other stages of the life cycle become more significant, such as materials selection, says Karen Rosenberg, research consultant, at RMIT Centre for Design. “Selecting materials from local sources, using materials with recycled content, choosing low-toxin products and looking for evidence that materials are from sustainable practices (such as chain of custody certification for timber) will have an increasing influence on the overall building performance,” she says.
The impact of construction techniques is another area that may receive attention in the future.
“For example, there is very little data available on the actual water and energy used in the process of building, and this may be significant when the standard level of energy efficiency is improved,” she says.
Some of the best examples of sustainable buildings are those that demonstrate an integrated approach to the design, whereby the project managers, engineers, builders, building designers and architects have a common goal.
“This can be a challenge to the building industry’s traditional linear approach to building design and construction, but the benefits can be vast,” Rosenberg says. “Early communication across multidisciplinary teams can lead to great innovation and in some cases, a more cost effective and buildable result.”
She says how a building consumes energy during the operational phase should be understood across all areas of the building process, “to ensure that the best features introduced at the design stage are not compromised at a later stage because their importance is not understood”.
Stephen Case, director at project and development management consultancy group Case Meallin & Associates, says the ecologically sustainable development initiatives that they’re seeing are water reuse, co-generation and the appropriate selection of building materials.
“All of these initiatives have become more commonplace over the last two to three years, as a result of heightened environmental awareness both within the marketplace and society as a whole,” he says.
Mellon says the principal challenge is in how we see buildings. “We need to move from the position of what can buildings do for us, to a position of what can developments add to our society, to our environment, what can they do for our economy.” He says, in terms of carbon, “some of the biggest, some of the best and some of the cheapest abatement opportunities come from the building sector”.
* When a building is occupied, about three-quarters of its emissions come from daily operations. During construction, half of these are emitted by machinery.
* In addition to machinery, much of the construction emissions come from the materials used and transporting the materials to the site.
* For businesses and their staff, producing a green travel plan, car pooling, and looking at the delivery route of materials can reduce emissions.