Instead of Asking How We Build, We Should Be Asking Why

We have to move beyond embodied carbon and seriously discuss avoided carbon.

Seeing the wood for the trees
Seeing the wood for the trees.

Camerique / Getty Images

The Association for Environment Conscious Building (AECB) is "a network of individuals and companies with a common aim of promoting sustainable building." Its CEO is designer and builder Andy Simmonds, who recently wrote an important article with Irish journalist Lenny Antonelli. He shared it with Treehugger but it is also published in full at Passive House +, under the title "Seeing the wood for the trees - Placing ecology at the heart of construction."

The issue of embodied carbon is one that the construction industry is just coming to grips with, as is the acceptance of mass timber. But Antonelli and Simmonds have been there and done that, and note that embodied carbon is "just the beginning." They have moved beyond the basic issues of carbon and to the larger question of what they call the biodiversity emergency.

Antonelli and Simmonds write:

"If climate change has been a rather nebulous concept, ecological collapse is arguably more so. It is happening all around us, yet is easy to miss because we are so disconnected from nature. It also challenges the idea that we can ‘fix’ environmental crises through technological solutions, instead requiring a complete reinvention of our relationship with food, materials, and the rest of the living world."

They question whether we can continue within a framework of endless growth, writing:

"Knowing how to respond effectively to ecological collapse is difficult from within a technological and growth-based mindset. But just like reducing our consumption of meat and dairy, which generally require more land than plant-based foods and thus put greater pressure on natural habitats, we can also seek to limit the area of land, and the quantity of raw natural resources, required to produce and maintain our buildings. We can also explore specifying materials that are, or could be, produced as integrated by-products of healthy ecosystems."

Antonelli and Simmonds are not the first to note that while we all love wood, it is not a magic bullet. We still have to rethink what and how much we build. Antonelli and Simmonds write:

"While material substitution — replacing high embodied carbon materials with lower embodied carbon ones — is important, it will never be sufficient within a growth-driven system. And it is not more important than fundamental measures such as building less and building more modestly, prioritising the retrofit of existing infrastructure, developing a genuine circular economy for building materials, and creating low land-use, zero-carbon construction materials."

The authors then get into many of the points we have discussed on Treehugger. Indeed, Simmonds acknowledges it and writes, "thanks for your own thinking that partly stimulated us to write this article in this way." You can read the full entry in each category on Passive House +. What follows is a commentary on it.


Clothes drying in Lisbon
Sufficiency in action in Lisbon.

Treehugger / Lloyd Alter

"Before building something, we should start by asking if it is really needed, and if there any strategic alternatives to the brief." Sufficiency has been a theme on Treehugger ever since we first learned the term from Kris de Decker. Sufficiency turned out to be key to my book, "Living the 1.5 Degree Lifestyle." I have been trying for years to convince readers that sufficiency is more important than efficiency. It's a hard sell; dryers are more convenient than clotheslines.


Nick Grant
Nick Grant explaining Value Engineering.

Treehugger / Lloyd Alter

"Designing and building as simply as possible — true value engineering or 'integrated design.'"

This is a concept we first learned from engineer Nick Grant, seen above explaining value engineering at a Passivhaus conference. Grant coined the term "radical simplicity" which I have noted we need right now.

Circular Economy

table made from bowling Alley
My cabin's table is made from an old bowling alley.

Treehugger / Lloyd Alter

"Explore circular design approaches. Design realistically for reuse and disassembly, be open about your assumptions for the end-of-life stage of buildings and products, in order to facilitate wider discussion and development."

I am late to the circular economy party; I thought it had been hijacked by the plastics industry as a fancy new name for recycling. I preferred to talk about design for disassembly or deconstruction. But I am coming round to the term. As Emma Loewe described it: "When applied to physical products, designing for circularity means creating things that can be reused multiple times or broken down into their constituent parts and then rebuilt into equally valuable items. It's about designing out that end-of-life step altogether and making objects that can stay in use, in some form, indefinitely."


Density of structural Timber
The density of structural timber used to achieve a given height of building for various structural systems.

 Renewable and Sustainable Energy Reviews, Volume 68, Part 1, February 2017,

When I have talked about radical efficiency, I am usually talking about operating energy and pushing Passivhaus. Antonelli and Simmonds use the word differently and are talking about design efficiency:

"Use natural resources extracted from our shared biosphere respectfully and efficiently to substitute for higher embodied carbon materials. Use as few materials as possible to achieve the design. Using a “renewable” material inefficiently, whether to ‘develop the market’ or ‘store carbon’ is wrongheaded – efficient use of the same quantity of material, substituting for higher carbon options across many projects, makes far more sense."

They reiterate a point that I have tried to make, usually unsuccessfully, that there is no reason to build with mass timber in low-rise when a light timber frame can do the job with a fifth as much fiber.

Antonelli and Simmonds continue with other points about being honest and transparent, becoming a systems thinker, and most importantly, connecting with the forest.

Four steps

As the first slide that I present to my students shows, my own list is shorter. Although, radical decarbonization should probably be two points: one about the energy supply (Electrify Everything!) and one about our buildings. What I find so significant about Antonelli and Simmond's article is that we are seeing a consensus developing, that we need a new way of looking at building. The World Green Building Council recently took this stance, noting we have to "question the need to use materials at all, considering alternative strategies for delivering the desired function, such as increasing utilisation of existing assets through renovation or reuse." 

As Jeff Colley, publisher of Passive House + notes, "I think the point for me is that articles like this like help up to unpack some really knotty (no pun intended) subjects, and to put us in a position to give some pretty clear advice on how to minimise the environmental impacts of buildings - whether to designers, punters, policy makers, etc. That feels very important."

Indeed, it is becoming obvious that we have to think about the environmental impacts of our buildings right now, with a hard ceiling on the carbon emissions that can be added to the atmosphere to stay under 2.7 degrees Fahrenheit (1.5 degrees Celsius) of warming. As Antonelli and Simmonds note, embodied carbon is just the beginning.

What's next? We need some type of term for avoided carbon. I recently wrote about what I called "organizational carbon emissions," a terrible name, trying to put a number on how much carbon is saved by not doing something, like going back to the office instead of working from home. I wrote:

"In our buildings, we have had the upfront or embodied carbon emissions from creating a building and the operating carbon emissions from running it. Now, we have a number for what might be called the organizational carbon emissions, which are a direct result of how we organize our businesses and the choices we make in how we run them—and it's huge."

Amory Lovins of the Rocky Mountain Institute used to talk about "negawatts" which "represents a watt of energy that you have not used through energy conservation or the use of energy-efficient products." As we get serious about what we don't build, perhaps we need to measure our negatonnes of carbon saved through simplicity, sufficiency, circularity, and material efficiency, or just not building anything at all.

Read the whole important article at Passive House +.