Niall Burke

Mar 06, 2023 • Overview

The Life Cycle of a Product According to BS EN 15978

In this post we take a high-level view of the product and material life cycle, breaking down the details and emissions per stage for ultra-low energy residential construction.


When calculating the emissions associated with a particular product or material, we look at those emissions with respect to the different stages of that product/material’s life.

Generally speaking, a product’s life is chopped up into 4 main stages: product, construction, use, and end-of-life. A Life Cycle Assessment (LCA) of a product will estimate the emissions produced during each of these stages.

There’s also a separate stage, usually referred to as “Beyond the Life Cycle”, that takes into account any positive or negative impacts the product may make outside of the life cycle. Typically, this stage is used to supply a metric of circularity, which is the ability of the product to contribute to a low carbon economy (an economy based on energy sources that produce low levels of greenhouse gas emissions – think renewables, like solar and wind).

So we have 4 life cycle stages and 1 oddball for beyond the life cycle. Let’s review these in a little more detail so we can really grasp what they mean.


Product Stage

The first stage. Inception. Our product is conceived in the earth as raw material and develops in the womb of the manufacturer.

This stage encapsulates emissions that are released during the extraction, processing and manufacture of the product. It also includes the transportation of the raw material to the manufacturer. It’s basically all emissions associated with creating a “thing”.

When talking about Product Stage emissions, sometimes you’ll see it referred to it as “cradle to gate”. Once we reach the gate, the manufacturer’s “baby” is all grown up and ready to go out into the big bad world.

In terms of total emissions, the Product Stage is typically responsible for around 50% of all emissions released over the course of a product’s life. Want to make a big dent in your emissions? Be prudent in your choice of products.


Key takeaways:

  • At 50% of all emissions, the Product Stage contributes more than any other stage
  • Product selection is key when aiming to reduce emissions

Note: the recycled content of a product will affect the quantity of emissions released during the Product Stage. Also, when conducting an LCA for a project we don’t account for any impact recycling may have on the emissions. Instead, those impacts are reserved for its afterlife i.e. Beyond the Life Cycle.

Construction Stage

Second up we have the Construction (Process) Stage. Here, we’re taking into account all the transport from the manufacturer to the construction site, any on-site activities that require energy (site huts, machinery, and the ever-present builder’s radio that’s a relic from a bygone era), and any processing of materials that are wasted due to the construction process (timber off-cuts etc.).

The end of the Construction Stage (or start of the Use Stage) is the practical completion of the project – it’s ready for active duty.


Use Stage

Our project is complete and is ready to be put to work. Emissions produced in this stage are related to the use, maintenance, repair, replacement and refurbishment of the product.

Of all these emissions, replacement is the most expensive. You’ll need to produce a new product, transport it to site and install it all over again. Also, remember that the Product Stage is responsible for approximately 50% of all emissions. Replacing products is expensive. Design for longevity where possible.

The Use Stage also covers other aspects, such as operational energy and water. That’s the electric to boil your kettle and the water to flush your toilet.

This stage gets the dubious honor of being runner up in the total emissions. The Use Stage is typically responsible for around 43% of all emissions. That said, 23% of the Use Stage emissions are down to operational energy use. This percentage is going to decrease over time as the electrical grid de-carbonizes, ultimately resulting in the Product Stage being responsible for an even higher percentage of the total emissions.


For example, if the electrical grid was carbon neutral, the Product Stage would account for 73% of all emissions. That’s massive. Again, be prudent in your choice of products.


Key takeaways:

  • The Use Stage is the second largest contributor to emissions
  • Emissions associated with this stage will reduce as the electricity grid de-carbonises

End of Life Stage

If the Product Stage is the birth of our product, the End-of-Life Stage is its death. This stage is associated with the emissions that arise as a result of decommissioning the product: stripping it out, demolition, deconstruction, and transportation away from the site for waste processing.

We’re not done yet though. At the waste processing plant, we need to account for the emissions that are generated due to the process of processing the waste product. Last but not least (actually it is close to least – this entire stage is responsible for about 2% of total emissions), we throw in the emissions due to the product’s disposal.


Beyond the Life Cycle

Great, we’ve made it through the life cycle, but what about the “Beyond” part. As said previously, this separate stage accounts for impacts that go beyond or are outside the scope of the product life cycle. Generally, the Beyond the Life Cycle stage is associated with benefits such as:

  • The recycling of products, or the inclusion of recycled products
  • Energy recovery (for example, the generation of energy through the incineration of timber products)
  • The reuse of products

The aim of the Beyond the Life Cycle Stage is to take a more holistic view of the product with respect to its environmental impact.

Get MasterSeries LCA

and start tracking your impact

Start free trial
An error has occurred. This application may no longer respond until reloaded. Reload 🗙