Suppliers delivering the goods on sustainability

• Geronimo Advisory Principal Willow Aliento reflects on the recent Concrete Masonry Association of Australia Innovation Forum
• Australian concrete masonry manufacturers are moving rapidly to adopt smart, low carbon and circular economy approaches for their operations
• Local government innovation is creating new solutions and market opportunities
• Permeable pavement can be a cornerstone of urban resilience retrofits

Delivering low carbon buildings and infrastructure is not just a top-down process that flows from developers, designers and specifiers down to the supply chain. As the recent Concrete Masonry Association of Australia Operations Innovation Forum showed, Australia’s suppliers and manufacturers are already moving ahead with sustainability innovation.

Clearly, the sector recognises the value proposition of reducing the emissions footprint of operations and products. Initiatives underway include energy efficiency improvements, implementing smart quality control and fabrication technology to reduce waste, improving water efficiency, and addressing the carbon footprint of raw materials.

Circular economy approaches, such as replacing virgin materials with materials such as fly ash or recycled crushed concrete or aggregate, and research and testing of lower carbon cements are being implemented.

Responding to ASRS requirements

Regulatory requirements for large companies and investors to report on carbon is shaping procurement contracts and specifications, and putting greater onus on the manufacturing sector to calculate and disclose carbon data. The work of CMAA CEO Cathy Inglis, Think Brick General Manager Jack Gill and their teams in leading a project with data analysts Rebuilt to develop Product Carbon Footprint (PCF) Documentation for every CMAA supplier member shows enormous leadership.

The PCF support also helps address the challenges some manufacturers may have with obtaining full Environmental Product Declarations (EPDs), which can be extremely expensive and require a much more detailed data and information gathering process. PCFs mean suppliers and manufacturers can meet the requirements of builders, developers and other clients that are targeting Green Star or NABERS Embodied carbon credits. It also ensures they are able to serve clients such as landscapers, local government and others that have internal carbon reduction and reporting strategies.

Supporting SME manufacturing

Without suitable credentials for the products, there is a risk small to medium local manufacturers and suppliers may find it more difficult to compete with larger organisations that have the resources to obtain full EPDs.

Given concrete masonry products may be procured in relatively small batches, for example, for a single residential project, or for the upgrade of a carpark or one street, it’s important smaller operators in the space remain viable. Also, local manufacturing is a vital part of ensuring regional economic security, reducing transport-related emissions and managing risk.

Concrete masonry as a building block for WSUD

The beneficial role concrete masonry products can play in urban settings was explored in the first part of the day, with a workshop on permeable pavements. It’s not an area of urban design that often receives much attention, but this might need to change as permeable pavements are an important tool in the kit for water sensitive urban design, urban heat management and road sharing.

Andrew King, Coordinator Engineering Services, City of West Torrens in South Australia, shared many examples of how council has been using permeable pavement solutions to substantially benefit urban greening and reduce urban heat, reduce stormwater runoff and flash flooding risks and improve traffic behaviour.

He stated that stormwater engineering affects every aspect of people’s lives, as it affects vegetation, amenity, safety, water quality and the longevity of built assets and infrastructure.

The examples he showed of how City of West Torrens has been identifying priority stress, designing and installing areas of permeable pavement, and then monitoring the benefits were inspiring. In particular, the rates of tree growth were stunning to see, in a city not known for being blessed with abundant year-round rainfall.

Another example was a massive old growth eucalypt that was causing cracks and uplift in a residential street, which was addressed by replacing the solid asphalt and concrete pavements with an area of permeable pavement around the tree. So, the local humans got to keep the shade, local animals for to retain the habitat, and the tree will be less likely to cause damage to the road surface. 

Getting out of the “pilot” mindset

An engineer by background, King made the point that presenting things as “pilot” or “demonstration” projects can be limiting.

These kinds of holistic approaches need to be business as usual. We don’t need more “pilots”.

King said in making a design or specification decision, there needs to be “multiple reasons for everything.” 

This sounds a lot like an ecological thinking approach to urban design, because in an ecology, every living thing has more than one role in the interconnected web.

In King’s context, that means a road does more than just help vehicles move from A to B; and a tree does more than just look attractive; and pavement does more than just provide a solid, stable and trafficable surface.

This is where permeable pavements, whether designed using interlocking concrete pavers with strategic gaps for water to move through, or using smart, porous concrete products that allow water to percolate through the paver wins compared to conventional solid concrete or tarmac.

Research shows holistic solutions deliver the goods

In his keynote presentation, Simon Beecham, Emeritus Professor in Sustainable Water Resources Engineering from University of South Australia, pointed out that conventional driveways “only do one thing” and this is a problem.

The footprint of the resources surely justifies a multi-purpose outcome, and he presented research that showed some of the co-benefits of permeable alternatives.

These include rectifying the acidic nature of rainfall – because all Australian rainfall is slightly acidic – as when water passes through concrete masonry products it becomes more alkaline, reducing the leaching of heavy metals.

A permeable area of paving for a driveway can also act as a water storage, and the captured water reticulated up to a home or other building for non-potable uses such as amenities flushing or used for irrigating landscape.

A research project involving an area of permeable pavement equivalent to one carpark, with a small solar panel and pump used to irrigate an area of adjacent landscaping required no additional watering – in South Australian climate conditions!

Another benefit of paving systems that enable water to percolate into the ground is tree roots then go deeper and broader below ground, instead of growing along the surface to try and gain water. In addition, where the soil is retaining more water, vegetation above ground has higher evapotranspiration rates, which means it has a stronger cooling effect on a hot day, as it is the evapotranspiration provides the most cooling, not just the physical shade, Beecham explained.  

The business case is solid

The most common argument against these kinds of solutions is cost. Beecham and King both explained that from a lifecycle cost perspective, permeable solutions can come out ahead. Maintainability and repairability is an important part of this. It’s always going to be cheaper to replace a few pavers than replace a whole area of solid pavement.

Where the permeable pavement is an element within an urban greening system, research led by Beecham has shown that the embodied carbon can be considered repaid within 12-15 years, and the research team looked at the optimal tree planting configuration to achieve this.

That should stack up for urban planners, infrastructure designers and local governments looking to make projects align with institutional carbon targets. It also adds another element to thinking about planning for resilience in the urban context.

Holistic solutions that can utilise local products that have a quantifiable carbon footprint, to manage climate effects that include heat and extreme rainfall, while adding to the robustness and amenity of the public domain are vital. It is extremely positive to see industry associations like CMAA and its members and stakeholders doing such excellent work to enable a positive approach to delivering sustainable solutions for streets, public open space and urban landscapes.

 Why I was there

As well as gaining additional insight into a material product that is very relevant for climate adaptation design, I was at the forum to present on rapid resilience assessments, integrating sustainability into business plans and risk management approaches, and understanding climate risk.

That included explaining how perceptions of risk associated with climate on the physical, regulatory and operational level can be managed through an opportunity perspective. For example, engaging with emissions reductions through reducing energy use is an opportunity to reduce costs for manufacturing.