As an industry, there has been a lot of focus on energy efficiency over the last decade in an attempt to reduce operational carbon from home energy use. And there has been some success, with CO2 emissions falling from around 6 tonnes per year for the average home to closer to 5 tonnes, as homes become more efficient, rooftop solar becomes more prevalent, and grids continue to green.
The SBA is proud to be at the vanguard of this change, providing practical guidance to better building as part of our mission to makenet zero sustainable homes mainstream.
But notice that word “sustainable”. That’s important.
While energy efficiency is essential, it is not the only environmental impact. Nor is it the largest. If you are only focusing on performance, you are missing a significant share of the environmental impacts our homes create, and leaving a major opportunity for a better outcome untouched.
So where do these impacts sit? They come from the materials we specify.
If we are not careful, material choices can lead to deforestation, habitat loss, pollution, resource depletion, health impacts, and high levels of embodied carbon.
A further consideration is that, as consumers of materials, builders and designers are responsible for millions of dollars of product specification. Our choices matter, and they send strong market signals.
By choosing more sustainable options, we not only minimise negative impacts on each project, we help shift the broader market. Thoughtful choices lead to better outcomes, not just for individual homes, but for the industry as a whole.
Think Low Carbon
On average, more than one tonne of CO2 has already been emitted for every square metre of a new home before it is even occupied. That means at least 200 tonnes of embodied carbon in the average build before the keys are handed over. As the grid continues to decarbonise, these projections show embodied carbon can significantly outweigh operational emissions.
High impact actions:
● Educate yourself. Review SBA Roadmap Step 2 for practical strategies and to understand the relative embodied carbon of common materials and assemblies.
● Specify a minimum 30% cement replacement in concrete using slag and/or fly ash blends to reduce carbon in footings.
● Source certified carbon neutral or offset products where available.
● Use and support products with Environmental Product Declarations (EPDs).
When choosing products, adopt the mindset: Think Low Carbon
Think Circular
39% of all waste in Australia comes from construction and demolition. If we want to be a truly sustainable society, we need to become more circular in how we use and reuse resources.
High impact actions:
● Re-use brick, timber and suitable materials from demolitions where possible.
● Choose products with recycled content.
● Design and build with deconstructability in mind. If it can’t be taken apart, its future is likely landfill.
● Recycle site waste wherever possible.
When choosing products, adopt the mindset: Think Circular
Think Habitat
Construction is responsible for roughly 50% of global resource use. This places enormous pressure on natural ecosystems and contributes to biodiversity loss.
High impact actions:
● Always consider timber source and follow SBA guidance when selecting timber.
● Refer to trusted resources such as the Mullum Creek Sustainable Timber Products list.
● Explore guides such as Breathe Architecture’s Guide to Sustainable Materials.
When choosing products, adopt the mindset: Think Habitat
Think Health
People spend most of their time indoors, much of that in their homes. There is nothing sustainable about an unhealthy home, no matter how energy efficient it is.
High impact actions:
● Prioritise good indoor air quality
○ Choose low VOC products
○ Check for low formaldehyde (E0) ratings in engineered timber products
○ Select Red List free materials
● Build to minimise condensation risk and prevent mould
When choosing products, adopt the mindset: Think Health
Final Thoughts
While this may feel like a lot, it is not an all or nothing exercise. Every improvement is still an improvement. Every better choice moves things in the right direction.
Start by introducing one or two new concepts or materials into each project, and build from there.
If you take nothing else from this, remember these four principles:
● Think Low Carbon
● Think Circular
● Think Habitat
● Think Health
And remember:
What we specify grows the market, and in time, becomes the market.
Sustainable material specification matters.
Your choices count.
