Greenwash Watch: Whole Life Carbon Assessments Are Being Questioned

It's tough to make predictions, especially when it's about carbon.

London Wall West
New Office Building at Barbican Centre doesn't look low-carbon.

City of London/ Diller Scofidio

Yogi Berra famously said, "It's tough to make predictions, especially about the future." But that is what consultants do with Whole Life Carbon Assessments (WLCAs); they are forecasts of the total carbon emissions that will be produced by a building from its creation, through its use, to its demolition. In North America, it is often called a Life Cycle Analysis (LCA). In the United Kingdom, where they take carbon in buildings more seriously than they seem to do in North America, WLCAs are often required for new building projects, especially when the demolition of existing buildings is involved. 

But Will Ing of the Architects' Journal writes that all is not well in the WLCA world. In a post titled "Whole-life carbon assessments—a whole new type of greenwash?", he writes, "They were meant to usher in a new era of low-carbon development. But instead, campaigners claim, they are being manipulated in some instances by canny developers able to exploit the lack of industry and planning know-how to spuriously justify demolition over refurbishment." He wonders, "Are these assessments really being subverted to provide cover for unsustainable business-as-usual development? Are they, in other words, just the latest form of greenwash?"

There are now dueling WLCAs, where a group fighting to preserve an existing building might produce one that says saving the existing building is better, while developers might produce another that claims the new building will have a lower carbon footprint in the end. Ing raises a couple of points that we have discussed on Treehugger:

"Given the urgent need to curb emissions in the face of the climate emergency, is it worse to emit a tonne of CO2 now, rather than half a century from now, when we might have better technology for absorbing CO2 emissions? If so, how should that be weighted in a WLCA?"
budget figures
This is how much carbon you can put into the air.


This is a critical point we covered in "Forget about Life Cycle Analyses; We Don't Have Time." We have hard ceilings limiting how much carbon we can add to the atmosphere. Every pound or kilogram that we add now goes against these numbers. So when we were discussing alternative names for embodied carbon, one of my suggestions was "here and now carbon" because that's what it is—we have the here and now to stop putting CO2 into the atmosphere. It's not just that I have a short attention span; the carbon we add to the atmosphere now matters more. This is the time value of carbon in action. As embodied carbon pioneer Larry Strain wrote,

"When we evaluate emission reduction strategies, there are two things to keep in mind: the amount of reduction, and when it happens. Because emissions are cumulative and because we have a limited amount of time to reduce them, carbon reductions now have more value than carbon reductions in the future. The next couple of decades are critical."

Ing then raises another point that we have discussed, which makes WLCAs like pinning jell-O to the wall:

"Under government plans, electricity from the National Grid will be fully decarbonised by 2035. This means that making an existing moderately insulated building very well insulated may not be justified under a WLCA, as the embodied carbon cost of the insulation itself might outweigh future operational carbon savings."

We first discussed this in "What do we need more: Insulation or Heatpumpification?", where engineer Toby Cambray noted that with a cleaner grid and the development of heat pumps, we could upgrade existing structures more efficiently and economically without going for deep energy retrofits. This led me further down the rabbit hole to what I pretentiously called the Ironclad Rule of Carbon:

What Is the Ironclad Rule of Carbon?

As our buildings become more efficient and we decarbonize the electricity supply, emissions from upfront or embodied carbon will increasingly dominate and approach 100% of emissions.

We are now at the point where, if the new building is electric, it is all upfront or embodied carbon. If we do a bit of insulation and heatpumpification of the existing building, it produces no operating carbon. So, really, you can come up with many different scenarios. I would take the position that, based on the ironclad rule, existing buildings always win.

And if you go back to Ing's question—"Are [these WLCAs] just the latest form of greenwash?"—it sounds like they could be. Simon Wyatt, sustainability partner at Cundall, appears to agree but notes that there are other reasons one might want to replace a building; just don't use the WLCA card. Ing writes: "While he says retrofit is almost always the lower carbon option, Wyatt also urges developers not to focus solely on carbon calculations and to justify demolition and new build 'in terms of its wider sustainability, social or economic value'."

Carl Elefante, second from right, 21 Oct 2022
Carl Elefante, second from right, 21 Oct 2022.

Lloyd Alter

I am writing this after spending the morning listening to a panel including Carl Elefante, who coined the phrase, "The greenest building is the one that is already built." I will be on a panel saying much the same after finishing this post, so it is fair to say that I have certain biases here. But in a changing, warming, electrifying world, it would seem that a Whole Life Carbon Assessment would be tough to pin down and that everyone would save a whole lot of time and energy if they just listened to Elefante.