CA50 - Embodied Carbon Data
Mass Timber Conference highlights, Embodied carbon data from Ramboll and more.
NEWSWORTHY
THE SPONSOR
Did you miss out on the International Mass Timber Conference?
Tour projects, attend workshops and meet the right people at their upcoming Summit!
Get the largest discount available [20%] with the code CARBONARCHITECT
THE TOPIC
The world of embodied carbon is just beginning to be understood.
Although LCA’s have been around for a long time, it doesn’t mean we’ve had data on buildings.
In-fact, for the most we still have very limited data on the embodied carbon of different buildings.
What we DO know is generally where carbon comes from in our buildings.
You’ve probably heard of the main culprits - Steel & Concrete.
They get a bad wrap, and partially for good reason.
But these aren’t the only factors to consider when specifying a structural system.
There are issues of fire, aesthetics, durability, and structural capacity to name a few.
But things are changing because carbon is entering the conversation.
So how much carbon does each structural system typically emit?
Well Ramboll has recently published some interesting data out of the UK.
You can take a look at some of the data yourself right HERE.
Concrete [750kg/m2] - 250kg/m2 - 900kg/m2
Concrete buildings are very common in high-rise residential construction buildings. Mass Timber is beginning to see a surge here, but historically tall residential towers are primarily concrete. Concrete is also often the optimal choice for buildings without a typically grid system because they rely less on a consistent column grid. Concrete buildings have the largest embodied carbon range as well as the highest median value. Like many thing, the devil is in the details. Larger spans and misaligned structural grids will raise this number.
Steel [700kg/m2] - 500kg/m2 - 900kg/m2
Steel buildings are quite common in most building types but not as much in residential. Steel is very versatile and can be very effective for both tall and short structures. Steel has the second highest median embodied carbon value, but still a pretty large range.
Mass Wood [600kg/m2] - 550kg/m2 - 650kg/m2
Mass Wood is beginning to find its way into every building type. From offices, to residential, to educational. Much of this is in hopes of lower embodied carbon which is demonstrated from these values. Mass Timber has the smallest range and the second lowest embodied carbon median value. The important thing to keep in mind is that it’s only 15-20% lower than the others.
Framed Wood [500kg/m2] - 450kg/m2 - 800kg/m2
Framed wood has the lowest value of the 4 systems but again has a pretty high range. Often wood framed buildings have lower overall heights and are much lighter which would cause smaller foundations and less seismic systems. Framed wood also has huge potential for prefabrication and material re-use.
If nothing else, it’s good to have some baselines as we begin to understand and design for low-embodied carbon buildings.
More importantly what I think I draw from this is that no mater the structural systems you are using, there is a huge range of embodied carbon possibilities.
A concrete building can have a lower embodied carbon impact than a wood building. It all depends on what you are building, how it engages the ground, how light it is, what you use for materials, and the list goes on and on.
How you design matters.
THE PERSON
Lloyd Alter is a name you may be familiar with if you’ve been reading anything on Tree Hugger. Now he writes via his personal Substack - Carbon Upfront and also on LinkedIn. He is also the Author of Living the 1.5 Degree Lifestyle - a book you should definitely check out.
THE PROJECT
The Stratford Pavilion in the UK is a landmark building that has a beautiful and dynamic form. The building used a timber frame to reduce the embodied carbon impact as well as reduce the construction timeline. Checkout this case study performed by LETI.
Just noticed the person thingie there, thank you! A lot of people will be (or should be) shocked by your structural system comparison, particularly since many in the industry claim that mass timber is storing carbon. I am not saying you are wrong in this (and I think many in the industry overstate the carbon savings from mass timber) but your statement "A concrete building can have a lower embodied carbon impact than a wood building." raises some serious questions.