THE TOPIC - LIFE CYCLE
If you’re curious where carbon fits within a construction project, a great place to start is to understand the life cycle stages. When I began studying carbon this confused the h-e-double hockey sticks out of me (yes, I’m a Canadian if you were wondering). In hopes of speeding that process up for you, this week’s newsletter is all about understanding the basics of life cycle stages and the associated carbon emissions.
Let’s start with the chart below from the World Green Building Council. It’s a summary of the stages and grouped with common terms.
There are a few terms you should recognize off the top. The first is embodied carbon, highlighted in light green, and the second is operational carbon, module B6. Whole life carbon is the combination of embodied and operational carbon.
Another term you should be familiar with is upfront carbon. This is typically the largest portion of embodied emissions on a project as it includes all the emissions required to produce the materials of the building. If you want to learn more about what that means check out my first newsletter - Upfront Emissions or if you want to look at the bigger concept of upfront emissions check out Lloyd Alters’ article The Upfront Carbon of Everything from Tea to Jeans.
Here are a few ways to look at this life cycle chart:
Upfront Carbon: Product Stage + Construction Process Stage
Upfront Carbon: A1 to A5
Embodied Carbon: A1 to A5 + B1 to B5 + C1 to C4
Operational Carbon: B6
Use Stage Embodied Carbon: B1 to B5
End of Life: C1 to C4
Whole Life Carbon: Upfront Carbon + Operational Carbon + End of Life Carbon
The key to this entire way of thinking is to consider all of a project’s life rather than just the beginning or just the operation. Consider what it will take to demolish or renovate the building, and how that impacts the environment.
THE GRAPHIC
WHY IT MATTERS
Carbon lingo matters for three primary reasons:
Learn to speak the language of carbon
Understand where carbon is being released in the process
Accurately compare materials to each other
Let’s dig a little deeper:
1 - Learn to speak the language of carbon
Whenever my wife and I go places we love to joke about archispeak. You know - facades, cantilever, soffits, gable, cornice. We’ve all been there, and it’s kinda fun. Well carbon, although less fun, has a similar language barrier.
For the average AEC professional, carbon is a very new topic especially when you are talking about embodied carbon. Like anything new, the importance of understanding the basic language and terminologies is important. The lifecycle stages of a project as outlined by EN 15978 is one of those terms and languages that is critical to understand if you are going to talk about carbon. As the industry changes it will be more common for owners, municipalities, and design professionals to speak the language.
2 - Understand where carbon is being released in the process
Materials have a total carbon emissions factor. For example, a specific carpet may have a value of 20kgCO2/m2. This is an overall metric for the product but doesn’t really give you a sense of where the emissions are coming from. Digging in deeper, a product EPD breaks this number down by the phases discussed above. A1-C4. So for that specific carpet, you may find that 50% of the emissions come from the extraction of the material and very little comes from the installation and replacement. This information isn’t overly insightful on some products, but on others it is. If you want to take a look at some EPD’s - take a look at Interface.
For example, let’s take a look at spray foam insulation Most of its emissions are not in the extraction or manufacturing process, but rather in the B1 Installation phase. This is because the gas released during the installation and off-gassing of the product results in significant emissions (highly dependent on the type of gas used).
3 - Accurately compare materials to each other
Materials can be very difficult to compare when it comes to carbon, especially if they do not have an EPD. With EPDs, materials are much easier to compare and contrast as the data is more explicit. We will talk further in future issues about the problems and pitfalls of EPD’s, but it’s important to note their importance moving forward.
Understanding the scope of emissions of each phase and how it compares to other phases will help you evaluate materials more consistently and understand where emissions are coming from. Without understanding what each phase means, you cannot properly compare them.
1 TIP - HOW TO REDUCE
First - learn about the life cycle phases so you know the language. Without the proper terminology, you will have difficulty reading an EPD.
Second - request and review EPDs for a few of the products on your project. Sometimes you get a blank stare - “what’s an EPD?” and sometimes you get an “of course we’d be happy to supply that”. Either way, the more designers request EPDs, the more comment they will become.
1 RESOURCE - TO HELP YOU ACT
EC3 is the best source for consolidated EPD data. You can also look on manufacturers’ websites, but this can be like pulling teeth and often has different ways of presenting the data.