Bridging the knowledge gap, what is an LCA and an EPD?

Life Cycle Assessments (LCA) and Environmental Product Declarations (EPD) are tools to calculate the environmental footprint, or impact, of a product or service. LCA’s and EPD’s can be used by any industry, government, or individual, who would like to understand more about the ecological impacts a product or service has on an environment. To simplify, a Life Cycle Assessment (LCA) is used to analyse a product or service, and an Environmental Product Declaration (EPD) is a summary of that analysis.

A Life Cycle Assessment (LCA) is a tool that identifies the environmental impact of a product or organisation throughout its life cycle. It quantifies the impacts of greenhouse gas emissions, energy use, water consumption, acidification, and ozone layer depletion by breaking down different inputs and outputs at each stage of a product’s life cycle. This includes raw material extraction, producing and using a product, transport, and disposal or re-use (cradle to grave). The results of an LCA can be used to drive sustainability improvements. This supports businesses in their goals by helping establish environmental targets and aiding decision-making for strategy development. Results can be used to report the environmental impact of a product or service to stakeholders, make environmental claims, and improve product design. 

LCA is a critical part of a sustainability strategy to support certifications such as an Environmental Product Declaration (EPD). An EPD is a standardised document detailing a product’s environmental and human health impact. The EPD is based on LCA calculations and provides a quantitative basis for the comparison of products and services. It is akin to a summary of an LCA that is compliant with specific guidelines, reviewed by a third party, and published on an online platform. Generally, an LCA is used internally and EPD’s are used externally to communicate environmental impact. Overall, both support and enhance an organisation’s sustainability strategy by contributing credible metrics to show how your company is developing and improving the sustainability of your product portfolio.

“EPD’s, underpinned by life cycle assessment (LCA), can provide an optimal approach to a more robust and consistent evaluation of the environmental performance of New Zealand buildings across the life cycle.” 

BRANZ report

Some see LCA’s and EPD’s as costs and others see them as investments. As a cost, they can be perceived as full of regulation, hoop jumping, and unnecessary expenditure of resource. On the other hand, by understanding your environmental impact, you can begin to minimise it. An LCA can illustrate inefficiencies and highlight hotspots in the value chain. These results can be utilised for strategy, goal-making, and communication with the market. Working toward improving these numbers can increase efficiency – better use of the human, time, and monetary resources available – and can result in better customer service, higher growth rates, and achievement of goals. Investment in EPDs and LCAs can simply help you do better. As markets morph, regulations change, and the world adapts to climate change, EPD’s and LCA’s are likely to become more prevalent. Those who move first and fast are inclined to have a significant advantage over those who play catch-up.

Interlink is currently at the beginning of our journey into LCA’s and EPD’s. Our understanding is that recycled railway sleepers and repurposed timbers are low-impact, reusable elements. When we collect these sleepers from shunting yards, wharves, or demolition sites, they have already ‘served their purpose’. This is to say that their embodied carbon and environmental impact have been fully calculated. Luckily for our customers, we save these resources and return them to market as beautiful, time-tested, charming rustic timbers, full of story, character, and minimal environmental impact. 

Reference and Further Reading

Introduction to LCA – The Life Cycle Association of New Zealand (

Environment and zero-carbon research | BRANZ

Building and construction | Ministry for the Environment

Measuring emissions: A guide for organisations: 2022 detailed guide | Ministry for the Environment

Measuring and reducing your emissions through the CNGP | Ministry for the Environment