Life has an end, but is there also an ‘end of life’, for products and buildings? Which is frequently used in science, like in building evaluations calculating with a maximum life span, but seems weird.
It is understandable in trade, for product developers, that want things to be replaced at some point, otherwise they won’t sell anything anymore. And for that reason usually also ensure that things do not last too long. Which is a result of measuring value in money, a system that strives for ‘more’. A system which of course has no scientific status or foundation in physics, when it comes to balanced resource use.
How about a product like a building. Technically, there is raw materials input ( ‘depletion’), of which a building is created. And that building can last for centuries. The examples can be found in every older city. As long as it is a good design (building physically and constructive), and is well maintained.
Apart from the raw materials input, there are two elements that are relevant for the impact: Firstly, the operational energy. Which is settled real time, regardless of how old a building is or will be, or whether it has a high or a low energy demand. That can even be changed during lifetime, if required. Besides operational there is embodied energy, the energy that has been put into materials, products and construction. This part is what is often averaged over that imaginary lifespan. Which in fact isn’t realistic, because that embodied energy is immediate, invested right at the start. The CO2 emissions are already in the air before the building is completed. So what do you need that lifespan for in that case?
Back to the raw materials . Which are also already ‘exhausted’ at the outset, with all their environmental (side) effects. Calculating with a lifespan use, would imply that regularly more materials have to be depleted, while they can last for hundreds of years ….
And then there is recycling and reuse. As soon as we assume that there is an end of life, we assume that things will then be reused or recycled… However that is the question of course! A) whether there is an end-of-life at all, and if so, B) whether or not there is recycling in that distant future. Its a bit wishful thinking. The point is, its not a scientific approach. While there are already so called scientific systems, such as LCA, in which future recycling can already be deducted as an advantage….!
In fact, calculating or evaluating with end of life shows that physical science has become completely entwined with economics, has become dependent on financial and investment mores.
“A building like this has to break down at some point, isn’t it? Any product does that, yes? “ And then we have to replace them and that’s how we keep working. Its assumed buildings must in fact start to fail after about 40 years and be declared uninhabitable after 50 years. So we can recycle them and build a new one.
But this kind of thinking has taken on a life of its own and has somehow made its way into science, or at least product and building evaluations. And so everyone accepts that approach: most methods or countries take 50 years as the end of life of buildings, others take 60 years, sometime even 40 or 80 years. In itself this already shows its nonsense, or just a financial optimisation.
In my view, this is a crossover from the non-beta science of economics to the yes-beta science of physical evaluation. And as such, this has eroded science.
Even a judge uses the criterion that a customer may expect “that a product will last for a reasonable period of time…” In other words: excepts that it only has a limited lifespan… ! And what is that assumption based on? And why not longer…? At the most you could say that you can expect that a product or house will be maintenance-free for a certain period of time….
Specifically in the case of buildings, where we invest upto x kg of raw material to house 1 kg of man , we have to assume that ‘ in principle’ it lasts forever, or can be repaired and remain to do so. As practice has proven. There is no established end of life. At least for buildings ,( and many products), things that are not part of an organic or ecological process*. No end of life.
Everything is always repairable, or can be made repairable. That it is sometimes difficult, so be it, (sometimes even intentionally made difficult because industry wants an end of life, think of the frustration not being able to unscrew a product to repair it!)
Fortunately, buildings are not (yet1) designed to collapse after 50 years. And neither do they. So calculating or averaging over such a period is also non sensical. The main structure, if properly designed and protected, can last for hundreds of years, even wood. Its only just parts that need to be maintained or parts that sometimes need to be replaced. Some roof tiles, a rain gutter, etc. But end of life of a building? Basically never. And certainly not scientifically.
Scientifically, you should calculate with a maintenance factor for a building: investment in raw materials to keep the building functional. For unlimited time. This should also be indicated in the initial design: the expected maintenance factor, in energy and material…. I’m afraid that a lot of architecture looks bad then… ( like the Rietveld Schroder house., to name just one…)
Science must evaluate purely on their physical impact. In theory, it could be that at a certain point the physical impact of keeping an individual building functional is larger than the physical impact of demolition and new construction. But that is seldom the case , and mostly only if external influences cause it, such as earthquakes, storms, groundwater degradation or the like. That sometimes buildings are regarded too bad to preserve is often the result of a financial decision , or of a fashionable decision, or because of a very bad original design, which entails very high maintenance efforts . It must be said, that also here our economic system is not cooperating: bad design with a lot of maintenance is good for GDP, because a lot of work.
But again, not so scientifically relevant.
Scientifically it is about how much energy and raw materials are needed to provide a certain function, per unit of time: So the impact per year of a m2 of floor. This is accepted for operational energy, the energy demand per m2 per year (but for which m2? About that next time…)
(and if operational energy is already required, see building 2226 )
But that also applies to the production impact, in energy and materials: x material and y energy have been invested to create a m2 of livable floor, and the longer that building lasts, the less material and energy was needed to provide that certain function for a certain time. This is a bit difficult to oversee for an individual building, its easier if we scale up to the level of building stock, for a city for instance. For London, for example, it could be calculated that x kg / year of material was needed per m2 of building per year (including maintenance) . In this way, not per building but per stock, you can calculate in real time just as with energy for material: in kg/year per m2, just like kWh per year per m2!  And if you can minimize that, regardless of the lifespan of 1 building, but while retaining its function, you are really doing well.
Incidentally, in itself this is also an example where science has been tempted, namely to look and evaluate per individual building, while that is irrelevant: physically its about the housing stock and the material ( and energy) flows through it!
If you allow me a little side step, its even not about buildings or products: when it comes to evaluating energy and material performance, in fact creating an analyses with system boundaries set around a building, or a product or a collection thereof, is resource wise completely irrelevant: to evaluate our impact on resources ( stocks) we have to evaluate the material or energy flow itself and the quality thereof in time.  Products or buildings, and even their functionalities, are only human concepts, completely irrelevant in the cycles of raw materials and energy: they are physically to be seen as already very degraded quality in that cycle, matter somewhere along the way from high concentrated quality to useless quality, that is: to chaotic dust in the background. But that just mentioned for completeness.
As long as construction-related science cannot escape the forces of the market and financial interests, science is of course a farce. This should be completely separated, and should use its own evaluation and calculation methods.**
And the assumption of an “end of life”, puts everything at a disadvantage from the start, then we will never get the optimal built environment, at least in terms of the environment and climate impacts.
Afterword ( was also posted as next blog ): Are buildings temporarely…? (2)
Therefore , calculating with an end of life today , is very shortsighted and only based on a continued misconception of unlimited availability of energy and resources. The same misconception that has brought us in current problems.
PS: If someone nevertheless wants to calculate with ‘lifespan’, then it should not be related to building but to CO2: : Then that should be totally 0 by 2050, or 28 years from now, at least, following the political chosen date.
In an absolute sense, its even before 2030, when we will have passed the 1.5 degree carbon budget (politics is always behind).
In other words: That means calculating with a lifespan of max 8 years: the time within buildings must be net 0-CO2 ( operational and embodied compensated). Still not ideal, but at least we’d be on the right track then. 
(see later added new insight in next article)
* Philosophically and especially evolutionary it is a different story: there must indeed be an end of life, otherwise progress is impossible. Then man would not have been there either, we arise from time and again new life, which has mutated and developed from previous life. As such there could be an end of life, in order to allow products or buildings to renew themselves. Yes, but that is only possible if the amount of material (and energy!) invested in it is maximized. If not, then the supply (and the energy for it) would have to be endless and that can’t be in a closed system, which the Earth is when it is about matter. So when it comes to products, it is important that they last as long as possible. At a certain point, the system can no longer afford additional products. At that point, something can only innovate against a steady state situation: giving up the mass (and provide the energy!) to make it into something new…(replacing, not adding). We are far from such a state, and the energy for it.
It would be interesting to consider what the maximum amount of mass that may be in circulation would then be. (of course also in relation to solar energy budget to shape or transform them) Although we have in fact already passed that maximum for a long time, we are eating heavily on our (concentrated) stocks.
* * The problem is: there are hardly any: there are hardly any good methodologies for evaluating resource cycles. And if attempted there are usually large gaps in the approach: Think of the discrimination between organic an non organic resources, when it comes to deal with renewability.
Lately, the construction industry, or rather society, and even science sometimes, has been fooled again with ‘circularity’ concept. Which is nothing else as ‘linear slowing down’ things. No doubt that’s needed, but not real circularity: closing cycles of (any) resources
 nav Rietveld Schroder house: http://www.ronaldrovers.com/architects-it-cant-be-santa-claus-forever/
 the kgh : http://www.ronaldrovers.com/the-kwhm2-and-the-kghm2-12/
 Gebroken Kringlopen. Naar een volhoudbaar gebruik van bronnen, Ronald Rovers, Uitg Eburon, isbn 9789463012034
and UK version: People vs Resources – restoring a world out of balance, Ronald Rovers, Publ. Eburon, isbn 9789463012553
1Een architect in Nederland heeft ooit een gebouw ontworpen dat in principe 20 jaar mee zou gaan ( project XX), en dan uiteen zou vallen in herbruikbare materialen. Idee is aardig, maar niet relevant: iedere proces stap vergroot de impact van functionele m2 in de tijd, zoals ik al eerder constateerde: alles iedere generatie zijn eigen gebouwde omgeving moest creëren, was vooruitgang onmogelijk.