Climate neutral building has a built-in dilemma: the building should not only be energy neutral or ZEB, but the material related CO2 emissions count as well. And these go up when operational demand goes down. This catch 22 could be addressed with the introduction of a limited budget for embodied energy investments, as proposed in the previous blog. Which does not say that we have solved it already in practice … [1]
But thats not all. Suppose we manage to find a way to make the building 0-(operational)energy, with a significant low embodied impact that by 2030 the building is net 0-CO2 emissions overall.
Then the next quest is to keep it climate-neutral. Its important that after the initial investment, the building remains 0-CO2 for the rest of its lifetime, for all maintenance and replacement of elements after 2030. The available CO2 budget has been spent on the initial investment, for building or renovation. If not , its double eating-in on the CO2 budget.
Which implies that materials used after 2030, should be 0-CO2 by themselves, for winning and production. As for instance the replacement of solar panels after 25 years should be a CO2 neutral operation. Which might imply that the panels have to be replaced three years before end of life, and donate the remaining 3 productive years to the production of new panels ( the EROI of PV panels ). In other words, to introduce energy-savings , as a new mandatory activity. If a building, more specific the owner, has not created a (renewable) energy budget, there is no room for new equipment…
Add the energy required for general maintenance, both for production as well as execution, and its clear that having a energy savings account becomes serious business. The only way out might be that industry went through a transition by that time, and is able to deliver 0- CO2 products. So that we even can built 0-embodied energy houses. How that might look like is for another blog.
Interesting is to see what is happening in the UK: Just this spring they abandoned a ambitious national strategy for houses to become carbon neutral. Now last week the London authorities have taken up the challenge , and introduced a city regulation: all new house should meet a new zero carbon requirement from now on, and if not the owner gets a fine ( in the order of £60 per tonne of carbon dioxide per year for a period of 30 years for the shortfall part) . [2] Protests all around of course, its framed as a new tax, since nobody can (or wants to) comply. But it can also be seen as a savings account: If the building is not 0, the financial budget can be used for a regional renewable energy production instead. ( whether the money will go their politically, has yet to be seen) . But is shows that the coming years we can expect very interesting actions and regulations, when climate-change will increase in political weight.
But even then, with a energy savings account, we are still not there. Its still only energy. The same story counts for materials: These should be generated beforehand, since otherwise the stocks will deplete too fast. For renewable materials thats obvious: you need first to have captured and binded CO2 , before its permitted to use it. And even more important: it applies as well for so called non renewables: Since why should these be allowed to deplete ? Saving at first, and again mainly energy for restoring stocks .[3]
So besides a energy savings account we will have a materials savings account: when window frames have to be replaced, a small piece of land will have already produced the wood. Remarkable is that several old castles and mansions in the UK, already planted trees hundred years ago , deliberately, to supply the wood for later maintenance. [4]
And its applied again, in our days: In Germany there is a eco-village “Sieben-Linden” , in the town of Poppau,which has 90 hectares of land in common ownership.[ Part of this is forest, to provide wood for heating and building materials: For maintenance a separate wood stock is preserved: a Material savings account in practice! [5]
Energy-neutral, climate-neutral, system-neutral
The most important thing is that we learn to handle a 0-CO2 approach, including materials. Not only address operational energy, but as well the embodied energy and the energy to restore stocks.
For our project its now defined as to retrofit the building for energy-neutral performance, with the intentions to limit the materials input to 14 years of substituted original operational energy. So it can be net climateneutral from 2030 on. To maintain climate-neutrality after 2030, requires the next step in strategy, which I named “ system-neutral” : there is no net environmental or CO2 impact over the lifetime of the project . Or else defined: system-neutral implies that the functionality of a m2 shelter can be provided permanently and resource/CO2 neutral .
If we take the Paris climate agreement serious, we can not only focus at 0-energy buildings. It requires a serious and new approach to bring CO2 levels permanently down. For environmental experts and researchers a enormous task to handle and provide guidance in this. To not just join a hype, but to develop effective approaches for absolute CO2 reduction. Otherwise it does not make much sense what we are doing. At least concerning climate agreements. And thats why everyone soon will have a energy and materials savings account. With guaranteed more interest as a financial savings account .
1 blog: Climate neutral in 2030: Catch 22 (1) , http://ronaldrovers.nl/?p=217
2 london: https://www.architectsjournal.co.uk/10011731.article
3 blog: Renewed or not-renewed , that’s the question. http://ronaldrovers.nl/?p=194
4 Foresty UK http://www.forestry.gov.uk/forestry/infd-6xjf5l
5 eco village Poppau: http://www.werkstatt-stadt.de/de/projekte/7/
