Counting the cost of construction with EPDs

8th Dec 2022

James Mortensen, Carbon Planning Associate, Slattery

The upfront embodied emissions generated in the construction industry are looming as a costly challenge. Many construction businesses are turning to carbon offsets. But offset prices are expected to increase over the next decade, and Slattery’s calculations suggest that just one medium sized commercial office building could face a bill for carbon offsetting to the tune of $6.6 million.

The best way to reduce the cost of carbon offsets is to generate less greenhouse gas emissions – and this is why Environmental Product Declarations are fast becoming the cornerstone of construction industry strategies to reduce upfront embodied carbon.

EPDs got off to a slow start in Australia’s construction industry – by mid-2015 we could still count the number of Australasian EPDs on three fingers. But today a rapidly growing number of companies understand the value of EPDs for their high quality, credible, transparent and third-party verified environmental impacts data that complies with international standards. This data improves the quality of upfront embodied carbon assessments, and it is for this reason that Slattery’s team uses as many EPDs in our carbon plans as we can.

Slattery is a locally owned and operated quantity surveying and cost advisory company that launched a market-leading Carbon Planning Service in early 2021. We use the measured quantities of materials from the cost plan and, rather than multiply the quantity of material by a dollar cost rate, we multiply it by the appropriate global warming potential (kg CO2 eq) rate, which we source from EPDs where possible.

Our Carbon Planning Service measures the upfront embodied carbon of a project throughout the various stages of design and highlights areas of carbon intensity. We provide alternative design and specification options to reduce upfront carbon, with indicative carbon and cost implications for each. We also benchmark measurements against other relevant projects.

Our work confirms that design solutions can be both cost and carbon effective. Striking the right balance requires careful data-backed decision-making – and that is entirely reliant on having the right data.

Where an EPD is not currently available, we source the data from the Australian Life Cycle Inventory (AusLCI) database. In a recent Slattery commercial office fitout carbon plan, EPD data accounted for more than 50% of the total project upfront carbon, with the remainder derived from AusLCI. As more EPDs are published, we expect this percentage to increase and further strengthen the quality of our reports and advice.

In a recent article for Built Economist, Chair of EPD Australasia Stephen Mitchell noted that all major voluntary building and infrastructure sustainability rating schemes have embraced EPDs as they turn their focus to measuring and reducing upfront embodied carbon (Mitchell, 2022).

Slattery is working with a range of industry stakeholders to help the National Australian Built Environment Rating System (NABERS) develop a new framework to measure, benchmark and certify embodied carbon from building materials and construction. Recent feedback from NABERS suggests that EPDs will be the preferred data source within the new framework. Green Star points are already up for grabs when project teams use EPDs, and they are also recognised by the Infrastructure Sustainability Council.

Climate Active, the Australian Government-backed carbon neutral certifier, recently published guidelines for measuring upfront embodied carbon in buildings. This includes an emissions data source order of preference, with EPDs second only to Climate Active carbon neutral certified products.

Meanwhile, developers, specifiers, and now carbon planners, are asking suppliers and manufacturers to provide EPDs for their products. Some supply chains, notably concrete, are ahead of the curve with small and large players embracing EPDs not just as a competitive differentiator but as a signal of innovation and leadership in sustainability.

We expect EPDs to become business-as-usual for most construction industry supply chains within just a few years. The competitive differentiator will not be whether a product has an EPD, but rather how its environmental impacts compare to competitors.

Decarbonisation is an obvious driver for EPDs, but they will also help the construction industry address other challenges, like waste generation, biodiversity loss and water scarcity. While tens of thousands of EPDs are now in global circulation, the scope for EPDs is as vast as the challenges ahead. As quantity surveyors and carbon planners count the cost of construction, the EPD is one of our most trusted tools in the toolbox.

Source: Stephen Mitchell, Built Economist, “EPDs and their role in the quantification of embodied carbon”. June-August 2022