By Dr Troy Coyle, Chief Executive Officer, NZ Heavy Engineering Research Association

In a world where sustainability is no longer a choice but a necessity, life cycle assessment emerges as a powerful tool to reshape the future of construction. It’s not just about reducing waste or managing resources; it’s about unlocking a blueprint for responsible innovation. 

Life cycle assessment (LCA) allows us to see the full picture of a building’s environmental impact, from raw material extraction to the end of its life. When we understand the total cost to the planet, we can make better choices – ones that serve not only our present, but also the generations to come.

In a nutshell, LCA is a method of assessing the environmental impacts of a product, process or service across all stages of its life cycle (from cradle to grave). For buildings, this spans raw material extraction (cradle); manufacturing and fabrication; building operation; maintenance; demolition and end-of-life use (grave) of building materials. General impact areas assessed include resource use, human health and ecological impacts. 

How is LCA performed?

The ISO 14000 series of environmental management standards inform LCA. In particular, ISO 14040:2006 ‘Environmental management – Life cycle assessment – Principles and framework’ and 14044:2006 ‘Environmental management – Life cycle assessment – Requirements and guidelines’ are the two underpinning standards for LCA.

Generally, LCA includes four steps:

1. Defining the goal and scope of the LCA: These must be clearly stated and must unambiguously describe:
   • the intended application
   • the rationale for the study
   • the intended audience for the LCA
   • whether the results will be used in a publicly released comparative assertion.
2. Inventory analysis: This requires compiling an inventory of relevant energy and material inputs, and environmental releases.
3. Impact assessment: This involves assessing the impact of the identified inputs and releases from step two.
4. Interpretation: Interpreting the results and providing decision support based on this.

Why should the construction sector embrace LCA?

Imagine a future where every building, bridge or structure we create isn’t just functional; it’s regenerative. LCA provides the metrics that make this future possible. With it, we can quantify the environmental impacts of every design decision and pinpoint where change is most needed. It does this by providing a quantitative assessment of impact to help inform decision-making.

Heavy Engineering Research Association (HERA), for example, has two projects in which LCA forms a key component of the research:

1. Our $10.3-million MBIE Endeavour Fund–supported project on Construction 4.0 is using LCA to evaluate the impacts of circular design on the carbon performance of buildings. This work is being led by Professor Sarah McLaren of Massey University. McLaren is also pioneering dynamic LCA approaches in Aotearoa New Zealand. This is a novel LCA approach that takes into account temporal differences in carbon emissions. Our project will be a pilot for the dynamic LCA approach that McLaren is developing.
2. Our steel research levy (HERA)- and building research levy (BRANZ)-supported project to develop design guidance for low-carbon design of steel and steel-hybrid, low-rise buildings also included LCA. It helped us to compare the carbon performance of various design changes against an ‘as built’ reference building. The LCA enables us to determine opportunities to pull out carbon in design.

LCA and the future of Construction 4.0

In the digital age, data is power. Construction 4.0 is transforming the sector by turning data into decision-making tools, and LCA is the linchpin in this transformation.

Our Construction 4.0 project uses LCA as a quantitative data source for evaluating and optimising circular design. Like any other dataset, Construction 4.0 can use this data to provide evidence-based decision support towards optimal multi-criteria design. For example, it can help design engineers to optimise design for carbon performance, while levers for seismic, affordability and constructability are also being pulled (that is the holistic nature of Construction 4.0).

We can’t afford to ignore LCA!

We are at a crossroads. The world is demanding more from us – more innovation, more responsibility, more foresight. LCA offers a way forward and a road map to help us lead the charge towards a more sustainable, resilient construction sector. By embedding LCA into our processes, we’re not just building better buildings, we’re building a future in which every choice counts, and every action contributes to the wellbeing of our planet and our people.

For more information, visit https://lcanz.org.nz/about.

About the author
Dr Troy Coyle brings more than 20 years’ experience in innovation management across a range of industries, including materials science, medical radiation physics, biotechnology, sustainable building products, renewable energy and steel. She is a scientist with a PhD from University of New South Wales, and has training in journalism and communications. She is the CEO of the NZ Heavy Engineering Research Association (HERA) – an impact-led independent research association focused on heavy engineering and its applications in manufacturing and construction.