LCA is not for practice. We need absolute energy indicators. 2/2

In many countries there is discussion at the moment about measuring the environmental impact of building ( and living ). [1] On the one hand of course the (operational) energy consumption, and how to deal with limited CO2 emission budgets. But on the other hand even more on the environmental impact of materials and building itself. And how to combine the two possibly.

And the main focus is on lca calculations, which has different categories combined, which are based on data from several databases which in turn are mainly based on environmental product declarations, EPDs, from mainly manufacturers or generic sources.

It is quite easy to see that at each step there is a certain bandwidth, and that all those bandwidths add up to a very vague and unreliable picture. And of course, starting from data mainly provided by industry, is already a big handicap.*.

However that is not even the biggest problem. The main problem is what you do with that data, and in this case its the idea that an lca is a the best approach to guide practice. While a lca is fine for scientists who know what they are doing, and know where the pitfalls are, and realize what is lacking, scientifically speaking. But its not suitable for practice. First of all, an lca often consists of multiple categories, with some categories related or consequential to each other. In other words, if 1 effect improves or worsens, often so does another effect. So basically you count gains or losses twice. Moreover: all these categories are effects, not causes. So we start at the end of the chain of interactions, correcting errors, instead of at the front, focusing at causes and with prevention.

But then: if more categories , these are usually combined into one number by means of a weighting factor: what they are worth in relation to each other (sometimes in case of ‘subcategories’, have a second weighing). And those weighing figures are subjective. Of course , chosen with educated guesses by scientists, but still subjective: there is no fundamental or scientific basis for, for example, weighing the impact of ocean acidification against human toxicity.

In some cases, as in the Netherlands, lca’s are used for an even stranger step: re-calculated for costs: they want to express end of pipe effects in money, because that’s what the market understands. While money by definition is not a great measure of sustainability or impact, after all it is not based on anything, When environmental or sustainability equations are made in money, you know in advance that you are being fooled: You create a fictitious , physically dimensionless, unit of account , call it money, and set up the system so that that money only has to grow and does so via consuming products and energy. So how can you ever expect that through that money there will be less impact? Exactly, so no one has an interest in impact, that is, everyone has an interest in everyone thinking that more money and investment will solve the problem. As Jason Hickel reported in a speech to the Dutch Parliament stated last week: green growth ( with money that is) , is trying to walk down an escalator going up.

Well, if sustainability could be profitable, we wouldn’t have a problem at all. Though that is exactly what we tell ourselves.

It is precisely the fact that money can be earned from the depletion and use of energy and raw materials that has got us into this mess. And that calculation exercise into money does not concern the value of the original resources, only the side effects. It only addresses fictitious “recovery’ costs. In other words, depletion is not the problem, as long as we calculate the damage. And just calculating, we are not even talking about real recovery or resources in most cases, If so, then in most cases its mainly greenwashing..

Our most prominent problem at the moment is climate disaster, mainly by CO2 emissions. By packaging it and weighing it together with countless other factors, prevents real focused results.

However, lately there is a tendency to use lca for only 1 aspect, CO2 emissions. Which avoids the weighing, which is good, but there are many flaws with addressing CO2 specific. The most important is that in that case we are still steering towards a consequence, not a cause.

There are many other imperfections in the way its calculated, as described in part 1 last time. One of the most important described was, that if we calculate in CO2, those CO2 emissions for the building materials are normalized over a fictitious life time. While they are already emitted today, and not in the distant future of the building. (Besides: If you normalize over the lifetime, say 50 years, then you have to count them as emissions every year for the next 50 years!).

Another ridiculous issue is to count recycling in the future , after lifetime, as an advantage for today (module D for the insiders) . That really is a greenwash. It implies thatpossible benefits for our children, using reused materials, are impossible, since its already discounted now. Later , in 50 years, you may no longer count the benefit of recycling then.

I am not in favor, but in case the focus is on CO2 emissions as the main indicator , the only really good way is to work with actual and absolute values. Don’t use lca, but use a direct and absolute requirement/value on CO2 emissions. ( and for today, not annualized)*.

And we have to change the boundary definition, since we are still only talking about one product, in this case a building, and even only per m2. We should relate the impact to what we as a country can and cannot afford, with limited CO2 budgets, and relate the budget to the whole stock. Or even better : focus at supply, the potential for renewing of resources, instead of calculating and evaluating the demand? Anyway, that seems too ambitious for the moment.

Better then focusing at CO2 however, is to take the cause as a starting point and focus at an absolute requirement on embodied energy. After all, we also have to limit energy use in the first place, as well as materials use. Even if the energy comes from renewable sources, the more energy demand the more construction of windmills and solar panels will be needed, so again more material and again more embodied energy. Ad infinitum. So less embodied energy, then the knife cuts both ways, and on the front end.

The embodied energy should also not be spread out over lifetime, so not shifting the problem to the future, but at the onset. After all, it’s already invested or emitted at inception.

For the Netherlands where we already have a required maximum (operational) energy demand for houses, as well as a of minimum renewable energy supplied ( still not ambitious enough, but that’s another issue). We can use the same methodology for embodied energy: steering on hard indicators. And similarly add two indicators: Beng 4 and 5 (Beng (1,2,3) is the general abbreviation for the regulations) : Beng 4 indicator sets a cap on embodied energy , and Beng 5 requires a minimum of renewable energy as part of that embodied energy. Fully in line with the approach for operational energy. It reduces both material use as well as energy use. (Besides, some other goals of a general lca will go down with it).

And not unimportant, its easy understandable for the whole building sector.

The discussion about how to include CO2 storage as in biobased materials is no longer necessary: with a low embodied energy requirement, biobased materials will be used in almost all cases! (as well as recycled and reused materials! The circular part)

What is not included then is what could be called ‘embodied material’: the regeneration of the stock of resources. With biobased of course, but especially with non-biobased , especially metals. These are not renewed, are rapidly becoming scarcer or require more and more energy to process, which is already a lot and for the time being still comes from fossil fuels, which in fact we can no longer afford. (Or again must come from solar or wind, but then again requires huge energy and materials investment). So ‘embodied material’ also has to come down.

Although, with BENG 4 and 5, most things will move in the right direction, towards biobased and less. And yes, these sometimes seem to work against each other, but it only seems that way: energy and materials are two of the same, the trick is to find the optimum, the lowest environmental impact for energy and materials together. And that may well lead to much less energy demand (e.g. by heating and insulating fewer rooms), in order to remain low in environmental impact.

So lets focus at direct and absolute calculations, and steering by causes, today.

What remains is to get the right and trustful data, because that is what is lacking: There is a need for an independent data authority, in the Netherlands but also in Europe. And not only for first order data, the data directly linked to a product, but also for upstream data: the secondary and tertiary embodied impacts: the construction of factories, infrastructure, production resources, etc.



* As was evident in recent weeks when the heat pump suddenly turned out to score much worse as expected (environmentally and material-wise) after a more serious look at data this time.

Data, and certainly good data, are essential, but a big problem. I wrote about it before, especially with regard to installations,[2].

I haven’t studied these new data but those are almost certainly still only primary process data. Not yet the impact of secondary and tertiary impacts, such as the impact of plant construction, labor, etc. It showed that here really needs to be an independent data authority, preferably in a European or IEA context.

** Denmark has already introduced solar CO2 budget for buildings larger than 1000 m2: 12 kg CO2 eq/m2 , and from 2025 for all buildings and homes: 10.5. A concrete absolute value. [3]. Too bad, it is per m2 , and unfortunately it is spread over 50 years, and it is scandalous that module D is included . But it’s a start, shall we say….


[1] for Dutch readers: a shorter version was published as opinion article in the building newspaper Cobouw:



How Denmark leads the way in decarbonising the construction industry

Author: ronald rovers