CA53 - Carbon Time Value
The importance of 10yr, 30yr, 60yr, RMI tool for upgrades, Mass Timber Group, and a materials expert.
NEWSWORTHY
🏠 RMI releases a new tool making it easier to crunch the costs of energy upgrades. USA only for now!
THE SPONSOR
Thanks to The Mass Timber Group for generously supporting this issue.
Get a 20% discount for their upcoming Summit with the code CARBONARCHITECT.
THE TOPIC
I’ve been pretty vocal about the need for architects to take a “whole-life carbon perspective”
What does that mean?
Well, it means we can’t just look at a carbon decision in today without considering how it impacts the future.
For example, it’s easy to say that adding exterior shading will lower the energy use of the building over time which lowers the operational footprint of the building.
True.
However, if the materials you use emit more carbon than they reduce, is it worth it?
Well, it might solve other problems (glare, overheating, etc) but that’s the importance of looking at things with a bigger and wider lens.
All that is true, we need to look at a building's entire life, not just the start and not just the finish.
One of the problems, however, is that most whole-life carbon data and information is focused on the 60-year lifecycle that is typically analyzed.
This leaves out the importance of the Time Value of Carbon.
This concept, as presented by the Carbon Leadership Forum, is that it’s more important to reduce carbon now than it is to reduce the same amount in the future.
This highlights the near term emissions and their importance.
To help present a clearer picture of this idea I’ve used some data from LETI.
I’ve mentioned this before, but I’ll mention it again…
If you haven’t looked at their resources, you should. LETI RESOURCES
In the Embodied Carbon Primer they break down the percentage of embodied vs operational carbon in code buildings + ultra-low energy buildings. However, this doesn’t illustrate the time value of carbon clearly.
When we extract the data and look at the 10-year and 30-year horizon a more stark story emerges.
Although over a 60-year time scale, embodied carbon in a code building is only 33% of the total emissions, it’s 66% after 10 years.
Contrast this with the ultra-low energy buildings and the split is more drastic with 92% of the emissions after 10 years being embodied emissions.
Again, this isn’t meant to challenge architects to stop looking at operational emissions.
What we are trying to do is think more about emissions today.
It’s so exciting seeing companies like TimberHP and Hempitecture getting a lot more traction as we make the transition to more biobased materials.
THE PERSON
Martha Lewis is the Head of Materials at Henning Larsen in Copenhagen. She has been working with HL for over 2 decades and has a wealth of knowledge of materials and their impact on the environment. She is certainly a leader in the field and a great person to follow.
THE PROJECT
The Harris Academy Sutton by Architype is the first Passivhaus secondary school in the UK. It is highly energy efficient and has a LCT structural system. The LCA revealed an upfront carbon intensity of 563 kgCO2e/m2.